1、隐式广播权限

android O系统后，隐式广播收到的限制，一定要指定包名才能发送出来。
否则会报错：
Background execution not allowed: receiving Intent { act=android.bluetooth.anw.action.PAIR_REQUEST flg=0x10 (has extras) } to com.anwsdk.sample/.BTMsgReceiver

但是在实际开发测试时，有些旧的app应用还是发送的隐式广播，导致接收不到，临时修改系统源码解决：
源码：\frameworks\base\services\core\java\com\android\server\am\BroadcastQueue.java
processNextBroadcastLocked()对广播进行了判断和处理：

       if (!skip) {
            final int allowed = mService.getAppStartModeLocked(
                    info.activityInfo.applicationInfo.uid, info.activityInfo.packageName,
                    info.activityInfo.applicationInfo.targetSdkVersion, -1, true, false, false);
            if (allowed != ActivityManager.APP_START_MODE_NORMAL) {
                // We won't allow this receiver to be launched if the app has been
                // completely disabled from launches, or it was not explicitly sent
                // to it and the app is in a state that should not receive it
                // (depending on how getAppStartModeLocked has determined that).
                if (allowed == ActivityManager.APP_START_MODE_DISABLED) {
                    Slog.w(TAG, "Background execution disabled: receiving "
                            + r.intent + " to "
                            + component.flattenToShortString());
                    skip = true;
                } else if (((r.intent.getFlags()&Intent.FLAG_RECEIVER_EXCLUDE_BACKGROUND) != 0)
                        || (r.intent.getComponent() == null
                            && r.intent.getPackage() == null
                            && ((r.intent.getFlags()
                                    & Intent.FLAG_RECEIVER_INCLUDE_BACKGROUND) == 0)
                            && !isSignaturePerm(r.requiredPermissions))) {
                    mService.addBackgroundCheckViolationLocked(r.intent.getAction(),
                            component.getPackageName());
                    Slog.w(TAG, "Background execution not allowed: receiving "
                            + r.intent + " to "
                            + component.flattenToShortString());
			
					//取消skip=true,让广播依旧可以发送出去
                    //skip = true;
                }
            }
        }

2、受保护的广播

报错：
ActivityManager: Sending non-protected broadcast …Throwable at

系统中发送的广播必须是受保护的广播，否则发送失败。

源码：\frameworks\base\core\res\AndroidManifest.xml

增加：

    <protected-broadcast android:name="android.intent.action.DOCK_IDLE" />
    <protected-broadcast android:name="android.intent.action.DOCK_ACTIVE" />