android 实现输入法的国际化


项目中有这么一个bug,即在切换语言后输入法没有实现国际化,只有重启设备输入法中的语言才会变过来即为正确的语言,后来经过下面的分析发现只要自己重启输入发服务就ok了,那么为什么会ok呢?下面已经说明


            先看我们怎么实现所有Activity展示的国际化,正常我们不会在原生态的setting中去实现,因为多数现在都是定制,我们也是,下面是我们自己的设置应用的语言切换实现功能代码:

	try {
		Class activityManagerNative = Class.forName("android.app.ActivityManagerNative");
		Object am = activityManagerNative.getMethod("getDefault").invoke(activityManagerNative);
		Object config = am.getClass().getMethod("getConfiguration").invoke(am);
                config.getClass().getDeclaredField("locale").set(config, language);
        	config.getClass().getDeclaredField("userSetLocale").setBoolean(config, true);
		am.getClass().getMethod("updateConfiguration", android.content.res.Configuration.class).invoke(am, config);
	} catch (Exception e) {
		
            	
        }

从上面可以看出,我们是通过反射的方法来调用了如下方法:

            IActivityManager am = ActivityManagerNative.getDefault();
            Configuration config = am.getConfiguration();
            config.locale = locale;           
            config.userSetLocale = true;
            am.updateConfiguration(config);
我们先获取到ActivityManagerNative的getDefault()对象,跟踪下这个代码

    /**
     * Retrieve the system‘s default/global activity manager.
     */
    static public IActivityManager getDefault() {
        return gDefault.get();
    }

    private static final Singleton<IActivityManager> gDefault = new Singleton<IActivityManager>() {
        protected IActivityManager create() {
            IBinder b = ServiceManager.getService("activity");
            if (false) {
                Log.v("ActivityManager", "default service binder = " + b);
            }
            IActivityManager am = asInterface(b);
            if (false) {
                Log.v("ActivityManager", "default service = " + am);
            }
            return am;
        }
    };

那么ServiceManager.getService("activity");获取的是什么对象呢?
在ActivityManagerService中有如下的定义:

    public static void setSystemProcess() {
        try {
            ActivityManagerService m = mSelf;
            
            ServiceManager.addService("activity", m);

从上面来看一个去addService一个去get,而get的对象就是ActivityManagerService,当然这里我是省事直接找到的,其实这个ActivityManagerService从启动到更改进程名称有个流程的,好吧,我们来看看ActivityManagerService的updateConfiguration(Configuration values)方法

    public void updateConfiguration(Configuration values) {
        enforceCallingPermission(android.Manifest.permission.CHANGE_CONFIGURATION,
                "updateConfiguration()");

        synchronized(this) {
            if (values == null && mWindowManager != null) {
                // sentinel: fetch the current configuration from the window manager
                values = mWindowManager.computeNewConfiguration();
            }

            if (mWindowManager != null) {
                mProcessList.applyDisplaySize(mWindowManager);
            }

            final long origId = Binder.clearCallingIdentity();
            if (values != null) {
                Settings.System.clearConfiguration(values);
            }
            updateConfigurationLocked(values, null, false, false);
            Binder.restoreCallingIdentity(origId);
        }
    }
上面的enforceCallingPermission方法进行权限验证,重点看updateConfigurationLocked(values, null, false, false);

   /**
     * Do either or both things: (1) change the current configuration, and (2)
     * make sure the given activity is running with the (now) current
     * configuration.  Returns true if the activity has been left running, or
     * false if <var>starting</var> is being destroyed to match the new
     * configuration.
     * @param persistent TODO
     */
    public boolean updateConfigurationLocked(Configuration values,
            ActivityRecord starting, boolean persistent, boolean initLocale) {
        int changes = 0;
        
        boolean kept = true;
        
        if (values != null) {
            Configuration newConfig = new Configuration(mConfiguration);
            changes = newConfig.updateFrom(values);
            if (changes != 0) {
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) {
                    Slog.i(TAG, "Updating configuration to: " + values);
                }
                
                EventLog.writeEvent(EventLogTags.CONFIGURATION_CHANGED, changes);

                if (values.locale != null && !initLocale) {
                    saveLocaleLocked(values.locale, 
                                     !values.locale.equals(mConfiguration.locale),
                                     values.userSetLocale);
                }

                mConfigurationSeq++;
                if (mConfigurationSeq <= 0) {
                    mConfigurationSeq = 1;
                }
                newConfig.seq = mConfigurationSeq;
                mConfiguration = newConfig;
                Slog.i(TAG, "Config changed: " + newConfig);

                final Configuration configCopy = new Configuration(mConfiguration);

                AttributeCache ac = AttributeCache.instance();
                if (ac != null) {
                    ac.updateConfiguration(configCopy);
                }

                // Make sure all resources in our process are updated
                // right now, so that anyone who is going to retrieve
                // resource values after we return will be sure to get
                // the new ones.  This is especially important during
                // boot, where the first config change needs to guarantee
                // all resources have that config before following boot
                // code is executed.
                mSystemThread.applyConfigurationToResources(configCopy);

                if (persistent && Settings.System.hasInterestingConfigurationChanges(changes)) {
                    Message msg = mHandler.obtainMessage(UPDATE_CONFIGURATION_MSG);
                    msg.obj = new Configuration(configCopy);
                    mHandler.sendMessage(msg);
                }
        
                for (int i=mLruProcesses.size()-1; i>=0; i--) {
                    ProcessRecord app = mLruProcesses.get(i);
                    try {
                        if (app.thread != null) {
                            if (DEBUG_CONFIGURATION) Slog.v(TAG, "Sending to proc "
                                    + app.processName + " new config " + mConfiguration);
                            app.thread.scheduleConfigurationChanged(configCopy);
                        }
                    } catch (Exception e) {
                    }
                }
                Intent intent = new Intent(Intent.ACTION_CONFIGURATION_CHANGED);
                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                        | Intent.FLAG_RECEIVER_REPLACE_PENDING);
                broadcastIntentLocked(null, null, intent, null, null, 0, null, null,
                        null, false, false, MY_PID, Process.SYSTEM_UID);
                if ((changes&ActivityInfo.CONFIG_LOCALE) != 0) {
                    broadcastIntentLocked(null, null,
                            new Intent(Intent.ACTION_LOCALE_CHANGED),
                            null, null, 0, null, null,
                            null, false, false, MY_PID, Process.SYSTEM_UID);
                }
            }
        }
        
        if (changes != 0 && starting == null) {
            // If the configuration changed, and the caller is not already
            // in the process of starting an activity, then find the top
            // activity to check if its configuration needs to change.
            starting = mMainStack.topRunningActivityLocked(null);
        }
        
        if (starting != null) {
            kept = mMainStack.ensureActivityConfigurationLocked(starting, changes);
            // And we need to make sure at this point that all other activities
            // are made visible with the correct configuration.
            mMainStack.ensureActivitiesVisibleLocked(starting, changes);
        }
        
        if (values != null && mWindowManager != null) {
            mWindowManager.setNewConfiguration(mConfiguration);
        }
        
        return kept;
    }

上面这个方法有点代码行比较多,我们先来看一下的注释,翻译下,呵呵,如下

(1)更改当前配置,通俗讲就是让改变的configuration更新到当前configuration

(2)确保所有正在运行的activity都能更新改变后的configuration

注释还是比较清晰的,我们重点看下面这个方法

for (int i=mLruProcesses.size()-1; i>=0; i--) {
                    ProcessRecord app = mLruProcesses.get(i);
                    try {
                        if (app.thread != null) {
                            if (DEBUG_CONFIGURATION) Slog.v("PateoConfig", "Sending to proc "
                                    + app.processName + " new config " + mConfiguration);
                            app.thread.scheduleConfigurationChanged(configCopy);
                        }
                    } catch (Exception e) {
                    }
                }

   /**
     * List of running applications, sorted by recent usage.
     * The first entry in the list is the least recently used.
     * It contains ApplicationRecord objects.  This list does NOT include
     * any persistent application records (since we never want to exit them).
     */
    final ArrayList<ProcessRecord> mLruProcesses
            = new ArrayList<ProcessRecord>();

从上面的注释来看,mLruProcesses保存所有运行过的进程.   一个apk文件运行时会对应一个进程. app.thread. 此处的thread代表的是什么呢?

    IApplicationThread thread; 
public abstract class ApplicationThreadNative extends Binder
        implements IApplicationThread {

从上面的实现来看是ApplicationThreadNative,好吧,我们进入该ApplicationThreadNative的scheduleConfigurationChanged方法:
    public final void scheduleConfigurationChanged(Configuration config)
            throws RemoteException {
        Parcel data = Parcel.obtain();
        data.writeInterfaceToken(IApplicationThread.descriptor);
        config.writeToParcel(data, 0);
        mRemote.transact(SCHEDULE_CONFIGURATION_CHANGED_TRANSACTION, data, null,
                IBinder.FLAG_ONEWAY);
        data.recycle();
    }

看看这个msg消息的处理

        case SCHEDULE_CONFIGURATION_CHANGED_TRANSACTION:
        {
            data.enforceInterface(IApplicationThread.descriptor);
            Configuration config = Configuration.CREATOR.createFromParcel(data);
            scheduleConfigurationChanged(config);
            return true;
        }
    void scheduleConfigurationChanged(Configuration config) throws RemoteException;
找到它的实现:

  private class ApplicationThread extends ApplicationThreadNative {
   
        ......
        public void scheduleConfigurationChanged(Configuration config) {
            updatePendingConfiguration(config);
            queueOrSendMessage(H.CONFIGURATION_CHANGED, config);
        }
        ......
}

来看看CONFIGURATION_CHANGED消息是怎么处理的

                case CONFIGURATION_CHANGED:
                    handleConfigurationChanged((Configuration)msg.obj, null);
                    break;

    final void handleConfigurationChanged(Configuration config, CompatibilityInfo compat) {

        ArrayList<ComponentCallbacks2> callbacks = null;

        synchronized (mPackages) {
            if (mPendingConfiguration != null) {
                if (!mPendingConfiguration.isOtherSeqNewer(config)) {
                    config = mPendingConfiguration;
                }
                mPendingConfiguration = null;
            }

            if (config == null) {
                return;
            }
            
            if (DEBUG_CONFIGURATION) Slog.v(TAG, "Handle configuration changed: "
                    + config);
        
            applyConfigurationToResourcesLocked(config, compat);
            
            if (mConfiguration == null) {
                mConfiguration = new Configuration();
            }
            if (!mConfiguration.isOtherSeqNewer(config) && compat == null) {
                return;
            }
            mConfiguration.updateFrom(config);
            config = applyCompatConfiguration();
            callbacks = collectComponentCallbacksLocked(false, config);
        }
        
        // Cleanup hardware accelerated stuff
        WindowManagerImpl.getDefault().trimLocalMemory();

        if (callbacks != null) {
            final int N = callbacks.size();
            for (int i=0; i<N; i++) {
                performConfigurationChanged(callbacks.get(i), config);
            }
        }
    }

我们先来看applyConfigurationToResourcesLocked(config, compat);

    final boolean applyConfigurationToResourcesLocked(Configuration config,
            CompatibilityInfo compat) {
    	if (DEBUG_CONFIGURATION) Slog.v("PateoConfig","ActivityThread class ,applyConfigurationToResourcesLocked coming");
        if (mResConfiguration == null) {
            mResConfiguration = new Configuration();
        }
        if (!mResConfiguration.isOtherSeqNewer(config) && compat == null) {
            if (DEBUG_CONFIGURATION) Slog.v(TAG, "Skipping new config: curSeq="
                    + mResConfiguration.seq + ", newSeq=" + config.seq);
            return false;
        }
        int changes = mResConfiguration.updateFrom(config);
        DisplayMetrics dm = getDisplayMetricsLocked(null, true);

        if (compat != null && (mResCompatibilityInfo == null ||
                !mResCompatibilityInfo.equals(compat))) {
            mResCompatibilityInfo = compat;
            changes |= ActivityInfo.CONFIG_SCREEN_LAYOUT
                    | ActivityInfo.CONFIG_SCREEN_SIZE
                    | ActivityInfo.CONFIG_SMALLEST_SCREEN_SIZE;
        }

        // set it for java, this also affects newly created Resources
        if (config.locale != null) {
            Locale.setDefault(config.locale);
        }

        Resources.updateSystemConfiguration(config, dm, compat);

        ApplicationPackageManager.configurationChanged();
        //Slog.i(TAG, "Configuration changed in " + currentPackageName());
        
        Iterator<WeakReference<Resources>> it =
            mActiveResources.values().iterator();
        //Iterator<Map.Entry<String, WeakReference<Resources>>> it =
        //    mActiveResources.entrySet().iterator();
        while (it.hasNext()) {
            WeakReference<Resources> v = it.next();
            Resources r = v.get();
            if (r != null) {
                if (DEBUG_CONFIGURATION) Slog.v("PateoConfig", "ActivityThread class ,Changing resources "
                        + r + " config to: " + config);
                r.updateConfiguration(config, dm, compat);
                //Slog.i(TAG, "Updated app resources " + v.getKey()
                //        + " " + r + ": " + r.getConfiguration());
            } else {
                //Slog.i(TAG, "Removing old resources " + v.getKey());
                it.remove();
            }
        }
        
        return changes != 0;
    }

Resources.updateSystemConfiguration()清除一部分系统资源, 并且将config更新到Resources, 而Resources包含了一个AssetManager对象, 该对象的核心实现是在AssetManager.cpp中完成的. 然后循环清空mActivityResources资源. 再回到handleConfigurationChanged()函数,执行下面的方法

 callbacks = collectComponentCallbacksLocked(false, config);

   ArrayList<ComponentCallbacks2> collectComponentCallbacksLocked(
            boolean allActivities, Configuration newConfig) {
        ArrayList<ComponentCallbacks2> callbacks
                = new ArrayList<ComponentCallbacks2>();

        if (mActivities.size() > 0) {
            Iterator<ActivityClientRecord> it = mActivities.values().iterator();
            while (it.hasNext()) {
                ActivityClientRecord ar = it.next();
                Activity a = ar.activity;
                if (a != null) {
                    Configuration thisConfig = applyConfigCompatMainThread(newConfig,
                            ar.packageInfo.mCompatibilityInfo.getIfNeeded());
                    if (!ar.activity.mFinished && (allActivities ||
                            (a != null && !ar.paused))) {
                        // If the activity is currently resumed, its configuration
                        // needs to change right now.
                        callbacks.add(a);
                    } else if (thisConfig != null) {
                        // Otherwise, we will tell it about the change
                        // the next time it is resumed or shown.  Note that
                        // the activity manager may, before then, decide the
                        // activity needs to be destroyed to handle its new
                        // configuration.
                        if (DEBUG_CONFIGURATION) Slog.v(TAG, "Setting activity "
                                + ar.activityInfo.name + " newConfig=" + thisConfig);
                        ar.newConfig = thisConfig;
                    }
                }
            }
        }
        if (mServices.size() > 0) {
            Iterator<Service> it = mServices.values().iterator();
            while (it.hasNext()) {
                callbacks.add(it.next());
            }
        }
        synchronized (mProviderMap) {
            if (mLocalProviders.size() > 0) {
                Iterator<ProviderClientRecord> it = mLocalProviders.values().iterator();
                while (it.hasNext()) {
                    callbacks.add(it.next().mLocalProvider);
                }
            }
        }
        final int N = mAllApplications.size();
        for (int i=0; i<N; i++) {
            callbacks.add(mAllApplications.get(i));
        }

        return callbacks;
    }

从上来看callbacks是Activity等被作为参数传入

if (callbacks != null) {
            final int N = callbacks.size();
            for (int i=0; i<N; i++) {
                performConfigurationChanged(callbacks.get(i), config);
            }
        }

进入performConfigurationChanged方法

    private final void performConfigurationChanged(
            ComponentCallbacks2 cb, Configuration config) {
        // Only for Activity objects, check that they actually call up to their
        // superclass implementation.  ComponentCallbacks2 is an interface, so
        // we check the runtime type and act accordingly.
        Activity activity = (cb instanceof Activity) ? (Activity) cb : null;
        if (activity != null) {
            activity.mCalled = false;
        }

        boolean shouldChangeConfig = false;
        if ((activity == null) || (activity.mCurrentConfig == null)) {
            shouldChangeConfig = true;
        } else {

            // If the new config is the same as the config this Activity
            // is already running with then don‘t bother calling
            // onConfigurationChanged
            int diff = activity.mCurrentConfig.diff(config);
            if (diff != 0) {
                // If this activity doesn‘t handle any of the config changes
                // then don‘t bother calling onConfigurationChanged as we‘re
                // going to destroy it.
                if ((~activity.mActivityInfo.getRealConfigChanged() & diff) == 0) {
                    shouldChangeConfig = true;
                }
            }
        }

        if (DEBUG_CONFIGURATION) Slog.v(TAG, "Config callback " + cb
                + ": shouldChangeConfig=" + shouldChangeConfig);
        if (shouldChangeConfig) {
            cb.onConfigurationChanged(config);

            if (activity != null) {
                if (!activity.mCalled) {
                    throw new SuperNotCalledException(
                            "Activity " + activity.getLocalClassName() +
                        " did not call through to super.onConfigurationChanged()");
                }
                activity.mConfigChangeFlags = 0;
                activity.mCurrentConfig = new Configuration(config);
            }
        }
    }
上面判断configuration是否改变, 如果改变那么shouldChangeConfig为true. 然后调用activity的onConfigurationChange(config);
  /**
     * Called by the system when the device configuration changes while your
     * activity is running.  Note that this will <em>only</em> be called if
     * you have selected configurations you would like to handle with the
     * {@link android.R.attr#configChanges} attribute in your manifest.  If
     * any configuration change occurs that is not selected to be reported
     * by that attribute, then instead of reporting it the system will stop
     * and restart the activity (to have it launched with the new
     * configuration).
     * 
     * <p>At the time that this function has been called, your Resources
     * object will have been updated to return resource values matching the
     * new configuration.
     * 
     * @param newConfig The new device configuration.
     */
    public void onConfigurationChanged(Configuration newConfig) {
        mCalled = true;

        mFragments.dispatchConfigurationChanged(newConfig);

        if (mWindow != null) {
            // Pass the configuration changed event to the window
            mWindow.onConfigurationChanged(newConfig);
        }

        if (mActionBar != null) {
            // Do this last; the action bar will need to access
            // view changes from above.
            mActionBar.onConfigurationChanged(newConfig);
        }
    }

看上面的注释意思:如果你的activity运行 , 设备信息有改变(即configuration改变)时由系统调用. 如果你在manifest.xml中配置了configChnages属性则表示有你自己来处理configuration change. 否则就重启当前这个activity.  而重启之前, 旧的resources已经被清空, 那么就会装载新的资源, 整个过程就完成了语言切换后 , 能够让所有app使用新的语言.


那么我们要问真正实现重启Activity的代码在哪呢,我们回到ActivityManagerService的updateConfigurationLocked方法,在我们分析完app.thread.scheduleConfigurationChanged(configCopy);的代码后,其实在app.thread.scheduleConfigurationChanged(configCopy);该代码下面即在updateConfigurationLocked方法内,有这么一行代码

        if (changes != 0 && starting == null) {
            // If the configuration changed, and the caller is not already
            // in the process of starting an activity, then find the top
            // activity to check if its configuration needs to change.
            starting = mMainStack.topRunningActivityLocked(null);
        }
        
        if (starting != null) {
            kept = mMainStack.ensureActivityConfigurationLocked(starting, changes);

主要是
 kept = mMainStack.ensureActivityConfigurationLocked(starting, changes);
我们进入该方法

   /**
     * Make sure the given activity matches the current configuration.  Returns
     * false if the activity had to be destroyed.  Returns true if the
     * configuration is the same, or the activity will remain running as-is
     * for whatever reason.  Ensures the HistoryRecord is updated with the
     * correct configuration and all other bookkeeping is handled.
     */
    final boolean ensureActivityConfigurationLocked(ActivityRecord r,
            int globalChanges) {
    	
        if (mConfigWillChange) {
            if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                    "Skipping config check (will change): " + r);
            return true;
        }
        
        if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                "Ensuring correct configuration: " + r);
        
        // Short circuit: if the two configurations are the exact same
        // object (the common case), then there is nothing to do.
        Configuration newConfig = mService.mConfiguration;
        if (r.configuration == newConfig && !r.forceNewConfig) {
            if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                    "Configuration unchanged in " + r);
            return true;
        }
        
        // We don‘t worry about activities that are finishing.
        if (r.finishing) {
            if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                    "Configuration doesn‘t matter in finishing " + r);
            r.stopFreezingScreenLocked(false);
            return true;
        }
        
        // Okay we now are going to make this activity have the new config.
        // But then we need to figure out how it needs to deal with that.
        Configuration oldConfig = r.configuration;
        r.configuration = newConfig;

        // Determine what has changed.  May be nothing, if this is a config
        // that has come back from the app after going idle.  In that case
        // we just want to leave the official config object now in the
        // activity and do nothing else.
        final int changes = oldConfig.diff(newConfig);
        if (changes == 0 && !r.forceNewConfig) {
            if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                    "Configuration no differences in " + r);
            return true;
        }

        // If the activity isn‘t currently running, just leave the new
        // configuration and it will pick that up next time it starts.
        if (r.app == null || r.app.thread == null) {
            if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                    "Configuration doesn‘t matter not running " + r);
            r.stopFreezingScreenLocked(false);
            r.forceNewConfig = false;
            return true;
        }
        
        // Figure out how to handle the changes between the configurations.
        if (DEBUG_SWITCH || DEBUG_CONFIGURATION) {
            Slog.v(TAG, "Checking to restart " + r.info.name + ": changed=0x"
                    + Integer.toHexString(changes) + ", handles=0x"
                    + Integer.toHexString(r.info.getRealConfigChanged())
                    + ", newConfig=" + newConfig);
        }
        if ((changes&(~r.info.getRealConfigChanged())) != 0 || r.forceNewConfig) {
            // Aha, the activity isn‘t handling the change, so DIE DIE DIE.
            r.configChangeFlags |= changes;
            r.startFreezingScreenLocked(r.app, globalChanges);
            r.forceNewConfig = false;
            if (r.app == null || r.app.thread == null) {
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is destroying non-running " + r);
                destroyActivityLocked(r, true, false, "config");
            } else if (r.state == ActivityState.PAUSING) {
                // A little annoying: we are waiting for this activity to
                // finish pausing.  Let‘s not do anything now, but just
                // flag that it needs to be restarted when done pausing.
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is skipping already pausing " + r);
                r.configDestroy = true;
                return true;
            } else if (r.state == ActivityState.RESUMED) {
                // Try to optimize this case: the configuration is changing
                // and we need to restart the top, resumed activity.
                // Instead of doing the normal handshaking, just say
                // "restart!".
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is restarting resumed " + r);
                relaunchActivityLocked(r, r.configChangeFlags, true);
                r.configChangeFlags = 0;
            } else {
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is restarting non-resumed " + r);
                relaunchActivityLocked(r, r.configChangeFlags, false);
                r.configChangeFlags = 0;
            }
            
            // All done...  tell the caller we weren‘t able to keep this
            // activity around.
            return false;
        }
        
        // Default case: the activity can handle this new configuration, so
        // hand it over.  Note that we don‘t need to give it the new
        // configuration, since we always send configuration changes to all
        // process when they happen so it can just use whatever configuration
        // it last got.
        if (r.app != null && r.app.thread != null) {
            try {
                if (DEBUG_CONFIGURATION) Slog.v(TAG, "Sending new config to " + r);
                r.app.thread.scheduleActivityConfigurationChanged(r.appToken);
            } catch (RemoteException e) {
                // If process died, whatever.
            }
        }
        r.stopFreezingScreenLocked(false);
        
        return true;
    }

我们会发现上面的代码有日志输出

V/ActivityManager( 1265): Switch is restarting resumed ActivityRecord{41ad1e90 com.pateo.as.settings/.activity.SettingActivity}
V/ActivityManager( 1265): Relaunching: ActivityRecord{41ad1e90 com.pateo.as.settings/.activity.SettingActivity} with results=null newIntents=null andResume=true
I/ActivityManager( 1265): Switch is restarting resumed ActivityRecord{41ad1e90 com.pateo.as.settings/.activity.SettingActivity}

根据输出日志我们来看下,是走入了下面这个方法:

 relaunchActivityLocked(r, r.configChangeFlags, true);

    private final boolean relaunchActivityLocked(ActivityRecord r,
            int changes, boolean andResume) {
        List<ResultInfo> results = null;
        List<Intent> newIntents = null;
        if (andResume) {
            results = r.results;
            newIntents = r.newIntents;
        }
        if (DEBUG_SWITCH) Slog.v(TAG, "Relaunching: " + r
                + " with results=" + results + " newIntents=" + newIntents
                + " andResume=" + andResume);
        EventLog.writeEvent(andResume ? EventLogTags.AM_RELAUNCH_RESUME_ACTIVITY
                : EventLogTags.AM_RELAUNCH_ACTIVITY, System.identityHashCode(r),
                r.task.taskId, r.shortComponentName);
        
        r.startFreezingScreenLocked(r.app, 0);
        
        try {
            if (DEBUG_SWITCH) Slog.i(TAG, "Switch is restarting resumed " + r);
            r.forceNewConfig = false;
            r.app.thread.scheduleRelaunchActivity(r.appToken, results, newIntents,
                    changes, !andResume, new Configuration(mService.mConfiguration));
            // Note: don‘t need to call pauseIfSleepingLocked() here, because
            // the caller will only pass in ‘andResume‘ if this activity is
            // currently resumed, which implies we aren‘t sleeping.
        } catch (RemoteException e) {
            return false;
        }

        if (andResume) {
            r.results = null;
            r.newIntents = null;
            if (mMainStack) {
                mService.reportResumedActivityLocked(r);
            }
        }

        return true;
    }

上面主要的调用了

r.app.thread.scheduleRelaunchActivity(r.appToken, results, newIntents,
                    changes, !andResume, new Configuration(mService.mConfiguration));

我们来看看这个scheduleRelaunchActivity方法,是public interface IApplicationThread类中,其实现在ActivityThread中

        public final void scheduleRelaunchActivity(IBinder token,
                List<ResultInfo> pendingResults, List<Intent> pendingNewIntents,
                int configChanges, boolean notResumed, Configuration config) {
            requestRelaunchActivity(token, pendingResults, pendingNewIntents,
                    configChanges, notResumed, config, true);
        }

    public final void requestRelaunchActivity(IBinder token,
            List<ResultInfo> pendingResults, List<Intent> pendingNewIntents,
            int configChanges, boolean notResumed, Configuration config,
            boolean fromServer) {
        ActivityClientRecord target = null;

        synchronized (mPackages) {
            for (int i=0; i<mRelaunchingActivities.size(); i++) {
                ActivityClientRecord r = mRelaunchingActivities.get(i);
                if (r.token == token) {
                    target = r;
                    if (pendingResults != null) {
                        if (r.pendingResults != null) {
                            r.pendingResults.addAll(pendingResults);
                        } else {
                            r.pendingResults = pendingResults;
                        }
                    }
                    if (pendingNewIntents != null) {
                        if (r.pendingIntents != null) {
                            r.pendingIntents.addAll(pendingNewIntents);
                        } else {
                            r.pendingIntents = pendingNewIntents;
                        }
                    }
                    break;
                }
            }

            if (target == null) {
                target = new ActivityClientRecord();
                target.token = token;
                target.pendingResults = pendingResults;
                target.pendingIntents = pendingNewIntents;
                if (!fromServer) {
                    ActivityClientRecord existing = mActivities.get(token);
                    if (existing != null) {
                        target.startsNotResumed = existing.paused;
                    }
                    target.onlyLocalRequest = true;
                }
                mRelaunchingActivities.add(target);
                queueOrSendMessage(H.RELAUNCH_ACTIVITY, target);
            }

            if (fromServer) {
                target.startsNotResumed = notResumed;
                target.onlyLocalRequest = false;
            }
            if (config != null) {
                target.createdConfig = config;
            }
            target.pendingConfigChanges |= configChanges;
        }
    }

接着看下消息的处理

                case RELAUNCH_ACTIVITY: {
                    ActivityClientRecord r = (ActivityClientRecord)msg.obj;
                    handleRelaunchActivity(r);
                } break;

   private void handleRelaunchActivity(ActivityClientRecord tmp) {
        // If we are getting ready to gc after going to the background, well
        // we are back active so skip it.
        unscheduleGcIdler();

        Configuration changedConfig = null;
        int configChanges = 0;

        // First: make sure we have the most recent configuration and most
        // recent version of the activity, or skip it if some previous call
        // had taken a more recent version.
        synchronized (mPackages) {
            int N = mRelaunchingActivities.size();
            IBinder token = tmp.token;
            tmp = null;
            for (int i=0; i<N; i++) {
                ActivityClientRecord r = mRelaunchingActivities.get(i);
                if (r.token == token) {
                    tmp = r;
                    configChanges |= tmp.pendingConfigChanges;
                    mRelaunchingActivities.remove(i);
                    i--;
                    N--;
                }
            }

            if (tmp == null) {
                if (DEBUG_CONFIGURATION) Slog.v(TAG, "Abort, activity not relaunching!");
                return;
            }

            if (DEBUG_CONFIGURATION) Slog.v(TAG, "Relaunching activity "
                    + tmp.token + " with configChanges=0x"
                    + Integer.toHexString(configChanges));

            if (mPendingConfiguration != null) {
                changedConfig = mPendingConfiguration;
                mPendingConfiguration = null;
            }
        }

        if (tmp.createdConfig != null) {
            // If the activity manager is passing us its current config,
            // assume that is really what we want regardless of what we
            // may have pending.
            if (mConfiguration == null
                    || (tmp.createdConfig.isOtherSeqNewer(mConfiguration)
                            && mConfiguration.diff(tmp.createdConfig) != 0)) {
                if (changedConfig == null
                        || tmp.createdConfig.isOtherSeqNewer(changedConfig)) {
                    changedConfig = tmp.createdConfig;
                }
            }
        }
        
        if (DEBUG_CONFIGURATION) Slog.v(TAG, "Relaunching activity "
                + tmp.token + ": changedConfig=" + changedConfig);
        
        // If there was a pending configuration change, execute it first.
        if (changedConfig != null) {
            handleConfigurationChanged(changedConfig, null);
        }

        ActivityClientRecord r = mActivities.get(tmp.token);
        if (DEBUG_CONFIGURATION) Slog.v(TAG, "Handling relaunch of " + r);
        if (r == null) {
            return;
        }

        r.activity.mConfigChangeFlags |= configChanges;
        r.onlyLocalRequest = tmp.onlyLocalRequest;
        Intent currentIntent = r.activity.mIntent;

        r.activity.mChangingConfigurations = true;

        // Need to ensure state is saved.
        if (!r.paused) {
            performPauseActivity(r.token, false, r.isPreHoneycomb());
        }
        if (r.state == null && !r.stopped && !r.isPreHoneycomb()) {
            r.state = new Bundle();
            r.state.setAllowFds(false);
            mInstrumentation.callActivityOnSaveInstanceState(r.activity, r.state);
        }

        handleDestroyActivity(r.token, false, configChanges, true);

        r.activity = null;
        r.window = null;
        r.hideForNow = false;
        r.nextIdle = null;
        // Merge any pending results and pending intents; don‘t just replace them
        if (tmp.pendingResults != null) {
            if (r.pendingResults == null) {
                r.pendingResults = tmp.pendingResults;
            } else {
                r.pendingResults.addAll(tmp.pendingResults);
            }
        }
        if (tmp.pendingIntents != null) {
            if (r.pendingIntents == null) {
                r.pendingIntents = tmp.pendingIntents;
            } else {
                r.pendingIntents.addAll(tmp.pendingIntents);
            }
        }
        r.startsNotResumed = tmp.startsNotResumed;

        handleLaunchActivity(r, currentIntent);
    }

上面我们梳理下,调用了如下重要的三个方法

1、performPauseActivity(r.token, false, r.isPreHoneycomb());

2、handleDestroyActivity(r.token, false, configChanges, true);

3、handleLaunchActivity(r, currentIntent);


先来看第一个方法performPauseActivity

    final Bundle performPauseActivity(IBinder token, boolean finished,
            boolean saveState) {
        ActivityClientRecord r = mActivities.get(token);
        return r != null ? performPauseActivity(r, finished, saveState) : null;
    }

    final Bundle performPauseActivity(ActivityClientRecord r, boolean finished,
            boolean saveState) {
        if (r.paused) {
            if (r.activity.mFinished) {
                // If we are finishing, we won‘t call onResume() in certain cases.
                // So here we likewise don‘t want to call onPause() if the activity
                // isn‘t resumed.
                return null;
            }
            RuntimeException e = new RuntimeException(
                    "Performing pause of activity that is not resumed: "
                    + r.intent.getComponent().toShortString());
            Slog.e(TAG, e.getMessage(), e);
        }
        Bundle state = null;
        if (finished) {
            r.activity.mFinished = true;
        }
        try {
            // Next have the activity save its current state and managed dialogs...
            if (!r.activity.mFinished && saveState) {
                state = new Bundle();
                state.setAllowFds(false);
                mInstrumentation.callActivityOnSaveInstanceState(r.activity, state);
                r.state = state;
            }
            // Now we are idle.
            r.activity.mCalled = false;
            mInstrumentation.callActivityOnPause(r.activity);
            EventLog.writeEvent(LOG_ON_PAUSE_CALLED, r.activity.getComponentName().getClassName());
            if (!r.activity.mCalled) {
                throw new SuperNotCalledException(
                    "Activity " + r.intent.getComponent().toShortString() +
                    " did not call through to super.onPause()");
            }

        } catch (SuperNotCalledException e) {
            throw e;

        } catch (Exception e) {
            if (!mInstrumentation.onException(r.activity, e)) {
                throw new RuntimeException(
                        "Unable to pause activity "
                        + r.intent.getComponent().toShortString()
                        + ": " + e.toString(), e);
            }
        }
        r.paused = true;

        // Notify any outstanding on paused listeners
        ArrayList<OnActivityPausedListener> listeners;
        synchronized (mOnPauseListeners) {
            listeners = mOnPauseListeners.remove(r.activity);
        }
        int size = (listeners != null ? listeners.size() : 0);
        for (int i = 0; i < size; i++) {
            listeners.get(i).onPaused(r.activity);
        }

        return state;
    }

上面最重要的是调用了如下:

    mInstrumentation.callActivityOnPause(r.activity);

进入该方法

    /**
     * Perform calling of an activity‘s {@link Activity#onPause} method.  The
     * default implementation simply calls through to that method.
     * 
     * @param activity The activity being paused.
     */
    public void callActivityOnPause(Activity activity) {
        activity.performPause();
    }
 
  final void performPause() {
        mFragments.dispatchPause();
        mCalled = false;
        onPause();
        mResumed = false;
        if (!mCalled && getApplicationInfo().targetSdkVersion
                >= android.os.Build.VERSION_CODES.GINGERBREAD) {
            throw new SuperNotCalledException(
                    "Activity " + mComponent.toShortString() +
                    " did not call through to super.onPause()");
        }
        mResumed = false;
    }
从上面来看最终调用了生命周期中的onPause方法

我们再来看第二个方法 handleDestroyActivity(r.token, false, configChanges, true);

   private void handleDestroyActivity(IBinder token, boolean finishing,
            int configChanges, boolean getNonConfigInstance) {
        ActivityClientRecord r = performDestroyActivity(token, finishing,
                configChanges, getNonConfigInstance);
        if (r != null) {
            cleanUpPendingRemoveWindows(r);
            WindowManager wm = r.activity.getWindowManager();
            View v = r.activity.mDecor;
            if (v != null) {
                if (r.activity.mVisibleFromServer) {
                    mNumVisibleActivities--;
                }
                IBinder wtoken = v.getWindowToken();
                if (r.activity.mWindowAdded) {
                    if (r.onlyLocalRequest) {
                        // Hold off on removing this until the new activity‘s
                        // window is being added.
                        r.mPendingRemoveWindow = v;
                        r.mPendingRemoveWindowManager = wm;
                    } else {
                        wm.removeViewImmediate(v);
                    }
                }
                if (wtoken != null && r.mPendingRemoveWindow == null) {
                    WindowManagerImpl.getDefault().closeAll(wtoken,
                            r.activity.getClass().getName(), "Activity");
                }
                r.activity.mDecor = null;
            }
            if (r.mPendingRemoveWindow == null) {
                // If we are delaying the removal of the activity window, then
                // we can‘t clean up all windows here.  Note that we can‘t do
                // so later either, which means any windows that aren‘t closed
                // by the app will leak.  Well we try to warning them a lot
                // about leaking windows, because that is a bug, so if they are
                // using this recreate facility then they get to live with leaks.
                WindowManagerImpl.getDefault().closeAll(token,
                        r.activity.getClass().getName(), "Activity");
            }

            // Mocked out contexts won‘t be participating in the normal
            // process lifecycle, but if we‘re running with a proper
            // ApplicationContext we need to have it tear down things
            // cleanly.
            Context c = r.activity.getBaseContext();
            if (c instanceof ContextImpl) {
                ((ContextImpl) c).scheduleFinalCleanup(
                        r.activity.getClass().getName(), "Activity");
            }
        }
        if (finishing) {
            try {
                ActivityManagerNative.getDefault().activityDestroyed(token);
            } catch (RemoteException ex) {
                // If the system process has died, it‘s game over for everyone.
            }
        }
    }

 ActivityClientRecord r = performDestroyActivity(token, finishing,
                configChanges, getNonConfigInstance);

    public final ActivityClientRecord performDestroyActivity(IBinder token, boolean finishing) {
        return performDestroyActivity(token, finishing, 0, false);
    }

    private ActivityClientRecord performDestroyActivity(IBinder token, boolean finishing,
            int configChanges, boolean getNonConfigInstance) {
        ActivityClientRecord r = mActivities.get(token);
        Class activityClass = null;
        if (localLOGV) Slog.v(TAG, "Performing finish of " + r);
        if (r != null) {
            activityClass = r.activity.getClass();
            r.activity.mConfigChangeFlags |= configChanges;
            if (finishing) {
                r.activity.mFinished = true;
            }
            if (!r.paused) {
                try {
                    r.activity.mCalled = false;
                    mInstrumentation.callActivityOnPause(r.activity);
                    EventLog.writeEvent(LOG_ON_PAUSE_CALLED,
                            r.activity.getComponentName().getClassName());
                    if (!r.activity.mCalled) {
                        throw new SuperNotCalledException(
                            "Activity " + safeToComponentShortString(r.intent)
                            + " did not call through to super.onPause()");
                    }
                } catch (SuperNotCalledException e) {
                    throw e;
                } catch (Exception e) {
                    if (!mInstrumentation.onException(r.activity, e)) {
                        throw new RuntimeException(
                                "Unable to pause activity "
                                + safeToComponentShortString(r.intent)
                                + ": " + e.toString(), e);
                    }
                }
                r.paused = true;
            }
            if (!r.stopped) {
                try {
                    r.activity.performStop();
                } catch (SuperNotCalledException e) {
                    throw e;
                } catch (Exception e) {
                    if (!mInstrumentation.onException(r.activity, e)) {
                        throw new RuntimeException(
                                "Unable to stop activity "
                                + safeToComponentShortString(r.intent)
                                + ": " + e.toString(), e);
                    }
                }
                r.stopped = true;
            }
            if (getNonConfigInstance) {
                try {
                    r.lastNonConfigurationInstances
                            = r.activity.retainNonConfigurationInstances();
                } catch (Exception e) {
                    if (!mInstrumentation.onException(r.activity, e)) {
                        throw new RuntimeException(
                                "Unable to retain activity "
                                + r.intent.getComponent().toShortString()
                                + ": " + e.toString(), e);
                    }
                }
            }
            try {
                r.activity.mCalled = false;
                mInstrumentation.callActivityOnDestroy(r.activity);
                if (!r.activity.mCalled) {
                    throw new SuperNotCalledException(
                        "Activity " + safeToComponentShortString(r.intent) +
                        " did not call through to super.onDestroy()");
                }
                if (r.window != null) {
                    r.window.closeAllPanels();
                }
            } catch (SuperNotCalledException e) {
                throw e;
            } catch (Exception e) {
                if (!mInstrumentation.onException(r.activity, e)) {
                    throw new RuntimeException(
                            "Unable to destroy activity " + safeToComponentShortString(r.intent)
                            + ": " + e.toString(), e);
                }
            }
        }
        mActivities.remove(token);
        StrictMode.decrementExpectedActivityCount(activityClass);
        return r;
    }

上面代码重要的调用了如下:

 r.activity.performStop();和 mInstrumentation.callActivityOnDestroy(r.activity);

这两个方法重点的是stop当前的Activity并且destroy Activity

我们回到第三个方法handleLaunchActivity

   private void handleLaunchActivity(ActivityClientRecord r, Intent customIntent) {
        // If we are getting ready to gc after going to the background, well
        // we are back active so skip it.
        unscheduleGcIdler();

        if (r.profileFd != null) {
            mProfiler.setProfiler(r.profileFile, r.profileFd);
            mProfiler.startProfiling();
            mProfiler.autoStopProfiler = r.autoStopProfiler;
        }

        // Make sure we are running with the most recent config.
        handleConfigurationChanged(null, null);

        if (localLOGV) Slog.v(
            TAG, "Handling launch of " + r);
        Activity a = performLaunchActivity(r, customIntent);

        if (a != null) {
            r.createdConfig = new Configuration(mConfiguration);
            Bundle oldState = r.state;
            handleResumeActivity(r.token, false, r.isForward);

            if (!r.activity.mFinished && r.startsNotResumed) {
                // The activity manager actually wants this one to start out
                // paused, because it needs to be visible but isn‘t in the
                // foreground.  We accomplish this by going through the
                // normal startup (because activities expect to go through
                // onResume() the first time they run, before their window
                // is displayed), and then pausing it.  However, in this case
                // we do -not- need to do the full pause cycle (of freezing
                // and such) because the activity manager assumes it can just
                // retain the current state it has.
                try {
                    r.activity.mCalled = false;
                    mInstrumentation.callActivityOnPause(r.activity);
                    // We need to keep around the original state, in case
                    // we need to be created again.
                    r.state = oldState;
                    if (!r.activity.mCalled) {
                        throw new SuperNotCalledException(
                            "Activity " + r.intent.getComponent().toShortString() +
                            " did not call through to super.onPause()");
                    }

                } catch (SuperNotCalledException e) {
                    throw e;

                } catch (Exception e) {
                    if (!mInstrumentation.onException(r.activity, e)) {
                        throw new RuntimeException(
                                "Unable to pause activity "
                                + r.intent.getComponent().toShortString()
                                + ": " + e.toString(), e);
                    }
                }
                r.paused = true;
            }
        } else {
            // If there was an error, for any reason, tell the activity
            // manager to stop us.
            try {
                ActivityManagerNative.getDefault()
                    .finishActivity(r.token, Activity.RESULT_CANCELED, null);
            } catch (RemoteException ex) {
                // Ignore
            }
        }
    }

假设,我们把handleLaunchActivity方法注释掉,则我们应该会看到当前界面销毁,而又没有起Activity,则会黑屏,呵呵

上面重要的两个方法如下:

1、 Activity a = performLaunchActivity(r, customIntent);

2、 handleResumeActivity(r.token, false, r.isForward);

先来看performLaunchActivity方法

    private Activity performLaunchActivity(ActivityClientRecord r, Intent customIntent) {
        // System.out.println("##### [" + System.currentTimeMillis() + "] ActivityThread.performLaunchActivity(" + r + ")");


        ActivityInfo aInfo = r.activityInfo;
        if (r.packageInfo == null) {
            r.packageInfo = getPackageInfo(aInfo.applicationInfo, r.compatInfo,
                    Context.CONTEXT_INCLUDE_CODE);
        }


        ComponentName component = r.intent.getComponent();
        if (component == null) {
            component = r.intent.resolveActivity(
                mInitialApplication.getPackageManager());
            r.intent.setComponent(component);
        }


        if (r.activityInfo.targetActivity != null) {
            component = new ComponentName(r.activityInfo.packageName,
                    r.activityInfo.targetActivity);
        }


        Activity activity = null;
        try {
            java.lang.ClassLoader cl = r.packageInfo.getClassLoader();
            activity = mInstrumentation.newActivity(
                    cl, component.getClassName(), r.intent);
            StrictMode.incrementExpectedActivityCount(activity.getClass());
            r.intent.setExtrasClassLoader(cl);
            if (r.state != null) {
                r.state.setClassLoader(cl);
            }
        } catch (Exception e) {
            if (!mInstrumentation.onException(activity, e)) {
                throw new RuntimeException(
                    "Unable to instantiate activity " + component
                    + ": " + e.toString(), e);
            }
        }


        try {
            Application app = r.packageInfo.makeApplication(false, mInstrumentation);


            if (localLOGV) Slog.v(TAG, "Performing launch of " + r);
            if (localLOGV) Slog.v(
                    TAG, r + ": app=" + app
                    + ", appName=" + app.getPackageName()
                    + ", pkg=" + r.packageInfo.getPackageName()
                    + ", comp=" + r.intent.getComponent().toShortString()
                    + ", dir=" + r.packageInfo.getAppDir());


            if (activity != null) {
                ContextImpl appContext = new ContextImpl();
                appContext.init(r.packageInfo, r.token, this);
                appContext.setOuterContext(activity);
                CharSequence title = r.activityInfo.loadLabel(appContext.getPackageManager());
                Configuration config = new Configuration(mCompatConfiguration);
                if (DEBUG_CONFIGURATION) Slog.v(TAG, "Launching activity "
                        + r.activityInfo.name + " with config " + config);
                activity.attach(appContext, this, getInstrumentation(), r.token,
                        r.ident, app, r.intent, r.activityInfo, title, r.parent,
                        r.embeddedID, r.lastNonConfigurationInstances, config);


                if (customIntent != null) {
                    activity.mIntent = customIntent;
                }
                r.lastNonConfigurationInstances = null;
                activity.mStartedActivity = false;
                int theme = r.activityInfo.getThemeResource();
                if (theme != 0) {
                    activity.setTheme(theme);
                }


                activity.mCalled = false;
                mInstrumentation.callActivityOnCreate(activity, r.state);
                if (!activity.mCalled) {
                    throw new SuperNotCalledException(
                        "Activity " + r.intent.getComponent().toShortString() +
                        " did not call through to super.onCreate()");
                }
                r.activity = activity;
                r.stopped = true;
                if (!r.activity.mFinished) {
                    activity.performStart();
                    r.stopped = false;
                }
                if (!r.activity.mFinished) {
                    if (r.state != null) {
                        mInstrumentation.callActivityOnRestoreInstanceState(activity, r.state);
                    }
                }
                if (!r.activity.mFinished) {
                    activity.mCalled = false;
                    mInstrumentation.callActivityOnPostCreate(activity, r.state);
                    if (!activity.mCalled) {
                        throw new SuperNotCalledException(
                            "Activity " + r.intent.getComponent().toShortString() +
                            " did not call through to super.onPostCreate()");
                    }
                }
            }
            r.paused = true;


            mActivities.put(r.token, r);


        } catch (SuperNotCalledException e) {
            throw e;


        } catch (Exception e) {
            if (!mInstrumentation.onException(activity, e)) {
                throw new RuntimeException(
                    "Unable to start activity " + component
                    + ": " + e.toString(), e);
            }
        }


        return activity;
    }

上面重要的一句代码:

 mInstrumentation.callActivityOnCreate(activity, r.state);

    public void callActivityOnCreate(Activity activity, Bundle icicle) {
        if (mWaitingActivities != null) {
            synchronized (mSync) {
                final int N = mWaitingActivities.size();
                for (int i=0; i<N; i++) {
                    final ActivityWaiter aw = mWaitingActivities.get(i);
                    final Intent intent = aw.intent;
                    if (intent.filterEquals(activity.getIntent())) {
                        aw.activity = activity;
                        mMessageQueue.addIdleHandler(new ActivityGoing(aw));
                    }
                }
            }
        }
        
        activity.performCreate(icicle);
        
        if (mActivityMonitors != null) {
            synchronized (mSync) {
                final int N = mActivityMonitors.size();
                for (int i=0; i<N; i++) {
                    final ActivityMonitor am = mActivityMonitors.get(i);
                    am.match(activity, activity, activity.getIntent());
                }
            }
        }
    }

进入方法performCreate

    final void performCreate(Bundle icicle) {
        onCreate(icicle);
        mVisibleFromClient = !mWindow.getWindowStyle().getBoolean(
                com.android.internal.R.styleable.Window_windowNoDisplay, false);
        mFragments.dispatchActivityCreated();
    }

我们看到了调用了onCreate启动了

再回到第二个方法handleResumeActivity,同上面一步步跟踪下去调用了Resume


从上面来看,我们有几点需要总结下:

说明:输入法的国际化在cb中有Activity也有service,而输入法是服务,在InputMethodService的继承类中加入了onConfigurationChanged方法,所以会回调onConfigurationChanged方法,而我在这个方法里面做了kill动作,类似于上面的代码的Activity的重启

cb.onConfigurationChanged(config);
   public void KillPinyin(){
		 android.os.Process.killProcess(android.os.Process.myPid());

		 final ActivityManager am = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE); 
		 am.restartPackage(getPackageName());  
    }

现在有个疑问,即如果我不去重新覆盖 onConfigurationChanged方法会怎么样?呵呵,按规矩不去覆盖该方法应该像其他应用一样会自动实现国家化,会吗?它是不会的,不信你试试,为什么呢?这又是另一个课题了,呵呵,我也很想有人和我交流这个,即为什么不去覆盖此方法也不行呢?我现在没有时间写博客了,要做项目了




android 实现输入法的国际化,布布扣,bubuko.com

android 实现输入法的国际化

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