一.第一种方案

1.1.将客户应用 内置到system/app 也就是将应用提升至系统级别  需要注意的是要将依赖lib库 拷贝到system/lib 下面
静默升级 也需要 更新 或者添加的库以前没有的库    建议：使用到不需要更新的apk 或者手动更新 

二.第二种方案
2.1.预装应有 到system/preinstall 但不允许卸载  静默升级 推荐使用

 

仨.第二种方案 两种改法   OS  Android5.1

3.1.Fist 改法

拖动到删除按钮  直接识别到可不包名不让卸载

diff --git a/packages/apps/PackageInstaller/src/com/android/packageinstaller/UninstallerActivity.java b/packages/apps/PackageInstaller/src/com/android/packageinstaller/UninstallerActivity.java
index 449bfad..5d12be9 100755
--- a/packages/apps/PackageInstaller/src/com/android/packageinstaller/UninstallerActivity.java
+++ b/packages/apps/PackageInstaller/src/com/android/packageinstaller/UninstallerActivity.java
@@ -216,8 +216,13 @@ public class UninstallerActivity extends Activity implements OnCancelListener{
                 // Continue as the ActivityInfo isn't critical.
             }
         }
-
-        showConfirmationDialog();
+		
+        if((packageName != null)&& packageName.contains("com.gatsbt.life")){
+			Log.d("gatsby","UninstallerActivity uninstall com.gatsby.fucklife");
+			 System.exit(0);       			
+		}else {		
+        	showConfirmationDialog();
+		}		
     }
     
     public void OnCreateDialog(){

3.2.Second 改法  识别包名不显示 卸载按钮

a.packages\apps\Launcher3\src\com\android\launcher3\DeleteDropTarget.java

boolean useDeleteLabel = !useUninstallLabel && source.supportsDeleteDropTarget(); 

        if(info instanceof AppInfo){
        	AppInfo appInfo = (AppInfo) info;
        	if(appInfo.componentName.getPackageName().equals("fuck.your.gatsby")){        	
        	 useUninstallLabel = false;       	
        	} 

        }  　　　　

控制是否显示长按 “卸载” 的选项 

    @Override
    public void onDragStart(DragSource source, Object info, int dragAction) {
        boolean isVisible = true;
        boolean useUninstallLabel = !LauncherAppState.isDisableAllApps() &&
                isAllAppsApplication(source, info);
        boolean useDeleteLabel = !useUninstallLabel && source.supportsDeleteDropTarget();

        // If we are dragging an application from AppsCustomize, only show the control if we can
        // delete the app (it was downloaded), and rename the string to "uninstall" in such a case.
        // Hide the delete target if it is a widget from AppsCustomize.
        if (!willAcceptDrop(info) || isAllAppsWidget(source, info)) {
            isVisible = false;
        }
        if (useUninstallLabel) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
                UserManager userManager = (UserManager)
                        getContext().getSystemService(Context.USER_SERVICE);
                Bundle restrictions = userManager.getUserRestrictions();
                if (restrictions.getBoolean(UserManager.DISALLOW_APPS_CONTROL, false)
                        || restrictions.getBoolean(UserManager.DISALLOW_UNINSTALL_APPS, false)) {
                    isVisible = false;
                }
            }
        }

        if (useUninstallLabel) {
            setCompoundDrawablesRelativeWithIntrinsicBounds(mUninstallDrawable, null, null, null);
        } else if (useDeleteLabel) {
            setCompoundDrawablesRelativeWithIntrinsicBounds(mRemoveDrawable, null, null, null);
        } else {
            isVisible = false;
        }
        mCurrentDrawable = (TransitionDrawable) getCurrentDrawable();

        mActive = isVisible;
        resetHoverColor();
        ((ViewGroup) getParent()).setVisibility(isVisible ? View.VISIBLE : View.GONE);
        if (isVisible && getText().length() > 0) {
            setText(useUninstallLabel ? R.string.delete_target_uninstall_label
                : R.string.delete_target_label);
        }
    }

b. packages\apps\Settings\src\com\android\settings\applications\InstalledAppDetails.java

设置应用信息 卸载项目

mUninstallButton.setOnClickListener(this); 让点击无效

    private void initUninstallButtons() {
        mUpdatedSysApp = (mAppEntry.info.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0;
        final boolean isBundled = (mAppEntry.info.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
        boolean enabled = true;
        if (mUpdatedSysApp) {
            mUninstallButton.setText(R.string.app_factory_reset);
            boolean showSpecialDisable = false;
            if (isBundled) {
                showSpecialDisable = handleDisableable(mSpecialDisableButton);
                mSpecialDisableButton.setOnClickListener(this);
            }
            if (mAppControlRestricted) {
                showSpecialDisable = false;
            }
            mMoreControlButtons.setVisibility(showSpecialDisable ? View.VISIBLE : View.GONE);
        } else {
            mMoreControlButtons.setVisibility(View.GONE);
            if (isBundled) {
                enabled = handleDisableable(mUninstallButton);
            } else if ((mPackageInfo.applicationInfo.flags
                    & ApplicationInfo.FLAG_INSTALLED) == 0
                    && mUserManager.getUsers().size() >= 2) {
                // When we have multiple users, there is a separate menu
                // to uninstall for all users.
                mUninstallButton.setText(R.string.uninstall_text);
                enabled = false;
            } else {
                mUninstallButton.setText(R.string.uninstall_text);
            }
        }
        // If this is a device admin, it can't be uninstalled or disabled.
        // We do this here so the text of the button is still set correctly.
        if (mDpm.packageHasActiveAdmins(mPackageInfo.packageName)) {
            enabled = false;
        }

        // Home apps need special handling.  Bundled ones we don't risk downgrading
        // because that can interfere with home-key resolution.  Furthermore, we
        // can't allow uninstallation of the only home app, and we don't want to
        // allow uninstallation of an explicitly preferred one -- the user can go
        // to Home settings and pick a different one, after which we'll permit
        // uninstallation of the now-not-default one.
        if (enabled && mHomePackages.contains(mPackageInfo.packageName)) {
            if (isBundled) {
                enabled = false;
            } else {
                ArrayList<ResolveInfo> homeActivities = new ArrayList<ResolveInfo>();
                ComponentName currentDefaultHome  = mPm.getHomeActivities(homeActivities);
                if (currentDefaultHome == null) {
                    // No preferred default, so permit uninstall only when
                    // there is more than one candidate
                    enabled = (mHomePackages.size() > 1);
                } else {
                    // There is an explicit default home app -- forbid uninstall of
                    // that one, but permit it for installed-but-inactive ones.
                    enabled = !mPackageInfo.packageName.equals(currentDefaultHome.getPackageName());
                }
            }
        }

        if (mAppControlRestricted) {
            enabled = false;
        }

        mUninstallButton.setEnabled(enabled);
        if (enabled) {
            // Register listener
            mUninstallButton.setOnClickListener(this);
        }
    }