0

我创建了一个通过 AIDL 向外部活动发送命令的服务：在此活动绑定到服务后，它向服务发送回调，因此建立了双向通信并正常工作。

相反，当我想根据从服务接收到的命令更改应用程序的 UI 时，就会出现问题。我使用简单的 Toast 通知进行了测试，但出现了一些错误......

当通过 AIDL 接收到新命令时，调用外部活动的onExecute方法。如果我删除 Toast 通知，一切正常，但我需要根据从服务收到的命令更改 UI。

protected void onExecute(Bundle params) {
    Log.i(LOG_TAG, "onExecute(): " + params);

    if (params.containsKey("command01")) {
        Log.i(LOG_TAG, "onExecute(): " + params.getString("command01"));
        Toast
        .makeText(this, "Command 1...", Toast.LENGTH_SHORT)
        .show();
    }
    else if (params.containsKey("command02")) {
        Log.i(LOG_TAG, "onExecute(): " + params.getString("command02"));
        Toast
        .makeText(this, "Command 2...", Toast.LENGTH_SHORT)
        .show();
    }
    else {
        Log.w(LOG_TAG, "onExecute() - unknown command: " + params);
    }
}

下图为 LogCat 在出错时记录的日志：

05-07 12:45:30.676: W/dalvikvm(363): JNI WARNING: JNI method called with exception raised
05-07 12:45:30.676: W/dalvikvm(363):              in Ldalvik/system/NativeStart;.run ()V (CallStaticVoidMethodV)
05-07 12:45:30.676: W/dalvikvm(363): Pending exception is:
05-07 12:45:30.676: I/dalvikvm(363): Ljava/lang/RuntimeException;: Can't create handler inside thread that has not called Looper.prepare()
05-07 12:45:30.706: I/dalvikvm(363):    at android.os.Handler.<init>(Handler.java:121)
05-07 12:45:30.706: I/dalvikvm(363):    at android.widget.Toast.<init>(Toast.java:68)
05-07 12:45:30.706: I/dalvikvm(363):    at android.widget.Toast.makeText(Toast.java:231)
05-07 12:45:30.706: I/dalvikvm(363):    at org.example.android.applicationdemo.ApplicationDemoActivity.onExecute(ApplicationDemoActivity.java:130)
05-07 12:45:30.706: I/dalvikvm(363):    at org.example.android.applicationdemo.ApplicationDemoActivity$2.execute(ApplicationDemoActivity.java:100)
05-07 12:45:30.706: I/dalvikvm(363):    at org.example.android.servicedemo.IServiceCallback$Stub.onTransact(IServiceCallback.java:55)
05-07 12:45:30.706: I/dalvikvm(363):    at android.os.Binder.execTransact(Binder.java:320)
05-07 12:45:30.706: I/dalvikvm(363):    at dalvik.system.NativeStart.run(Native Method)
05-07 12:45:30.706: I/dalvikvm(363): "Binder Thread #2" prio=5 tid=8 NATIVE
05-07 12:45:30.706: I/dalvikvm(363):   | group="main" sCount=0 dsCount=0 obj=0x405116f0 self=0x1f1590
05-07 12:45:30.706: I/dalvikvm(363):   | sysTid=370 nice=0 sched=0/0 cgrp=default handle=2037072
05-07 12:45:30.714: I/dalvikvm(363):   | schedstat=( 18375041 37002039 19 )
05-07 12:45:30.714: I/dalvikvm(363):   at dalvik.system.NativeStart.run(Native Method)
05-07 12:45:30.714: E/dalvikvm(363): VM aborting
4

1 回答 1

1

我认为您在非 UI 线程上执行的方法中创建了您的 Handler。将您的 Handler 作为全局变量。

private Handler _handler = new Handler();
于 2012-05-07T13:12:14.107 回答