Receiver not registered.

1. 在MessageListActivity中出现异常：Receiver not registered.

07-16 11:15:47.881: E/AndroidRuntime(32361): FATAL EXCEPTION: main
07-16 11:15:47.881: E/AndroidRuntime(32361): java.lang.RuntimeException: Unable to destroy activity {com.txrj.sms/com.txrj.sms.activity.MessageListActivity}: java.lang.IllegalArgumentException: Receiver not registered: com.txrj.sms.activity.MessageListActivity$6@41dd73f0
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3129)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3147)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ActivityThread.access$1200(ActivityThread.java:128)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1194)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.os.Looper.loop(Looper.java:137)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ActivityThread.main(ActivityThread.java:4517)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at java.lang.reflect.Method.invokeNative(Native Method)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at java.lang.reflect.Method.invoke(Method.java:511)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at dalvik.system.NativeStart.main(Native Method)
07-16 11:15:47.881: E/AndroidRuntime(32361): Caused by: java.lang.IllegalArgumentException: Receiver not registered: com.txrj.sms.activity.MessageListActivity$6@41dd73f0
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.LoadedApk.forgetReceiverDispatcher(LoadedApk.java:628)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ContextImpl.unregisterReceiver(ContextImpl.java:1190)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.content.ContextWrapper.unregisterReceiver(ContextWrapper.java:361)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at com.txrj.sms.activity.MessageListActivity.onDestroy(MessageListActivity.java:327)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.Activity.performDestroy(Activity.java:4634)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1083)
07-16 11:15:47.881: E/AndroidRuntime(32361):     at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3116)
07-16 11:15:47.881: E/AndroidRuntime(32361):     ... 11 more

2. 查看BroadcastReceiver API文档，了解到广播的onReceive方法执行完，然后广播就不再处于active状态了。所以当发出信息成功之后，通过Toast.makeText弹出提示告知用户，然后onReceive方法结束，广播的生命周期就结束了。从中还了解到onReceive方法中可以执行Toast.makeText()表现了广播的onReceive方法是在主线程中执行的，否则就无法执行Toast.makeText方法了。

private void createAndRegisterDeliveryIntent() {
    deliveryReceiver = new BroadcastReceiver(){

        @Override
        public void onReceive(Context context, Intent intent) {
            mContext.unregisterReceiver(this);
           Toast.makeText(context, "message arrived.", Toast.LENGTH_SHORT).show();
        }
    };
    IntentFilter filter = new IntentFilter(TxrjConstant.ACTION_DELIVERY_SMS);
    mContext.registerReceiver(deliveryReceiver, filter);
}

3. 查看上面的代码片段红色部分。这条语句不应该出现。因为在Activity的onDestroy()方法中调用了注销方法。