为什么在调用的远程服务方法中不能使用Toast

[syy19930112]

我有一个名为‘支付通’的应用，它提供了aidl,可以是其他应用调用它的服务。我现在的问题是，如果我在远程服务的方法中使用了Toast.markText方法时就会报一下的错误

11-15 13:25:12.338: E/JavaBinder(4410): *** Uncaught remote exception!  (Exceptions are not yet supported across processes.)
11-15 13:25:12.338: E/JavaBinder(4410): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
11-15 13:25:12.338: E/JavaBinder(4410): 	at android.os.Handler.<init>(Handler.java:197)
11-15 13:25:12.338: E/JavaBinder(4410): 	at android.os.Handler.<init>(Handler.java:111)
11-15 13:25:12.338: E/JavaBinder(4410): 	at android.widget.Toast$TN.<init>(Toast.java:324)
11-15 13:25:12.338: E/JavaBinder(4410): 	at android.widget.Toast.<init>(Toast.java:91)
11-15 13:25:12.338: E/JavaBinder(4410): 	at android.widget.Toast.makeText(Toast.java:238)
11-15 13:25:12.338: E/JavaBinder(4410): 	at com.zyt.remoteservice.PlayService.playfollow(PlayService.java:41)
11-15 13:25:12.338: E/JavaBinder(4410): 	at com.zyt.remoteservice.PlayService.access$0(PlayService.java:39)
11-15 13:25:12.338: E/JavaBinder(4410): 	at com.zyt.remoteservice.PlayService$MyBinder.play(PlayService.java:35)
11-15 13:25:12.338: E/JavaBinder(4410): 	at com.zyt.remoteservice.IPlayService$Stub.onTransact(IPlayService.java:48)
11-15 13:25:12.338: E/JavaBinder(4410): 	at android.os.Binder.execTransact(Binder.java:351)
11-15 13:25:12.338: E/JavaBinder(4410): 	at dalvik.system.NativeStart.run(Native Method)

我想知道为什么远程调用服务的时候不能在服务中使用Toast.markText。为什么本地应用中调用Service的方法的时候，方法体中可以使用Toast.markText。

[Birds2018]

Can't create handler inside thread that has not called Looper.prepare() 这个意思是很明显， 子线程是没有消息队列的，需要这样写：

new Thread(){
  public void run(){
    Looper.prepare();
    myLooper = Looper.myLooper();
    Looper.loop();
  }
}.start();
把上面的myLooper传给handler

Handler handler = new MyHandler(myLooper);

[tcmakebest]

原因是不在主线程，需要用线程通讯的方法到主线程中进行操作，具体方法是： 1 在 onCreate 方法就是主线程中新建一个 Handler，并实现 2 在子线程中发送消息给第一步的对象发送一个消息，可以附带相关数据

h = new Handler() {
	@Override
	public void handleMessage(Message msg) {
		super.handleMessage(msg);
		switch(msg.what) {
		case 0:
			Toast.makeText(c, msg.obj.toString(), Toast.LENGTH_LONG).show();
			break;
		}

	}
};

Message msg = new Message();
msg.what = 0;
msg.obj = "show text";
h.sendMessage(msg);