ServiceConnection总是将错误返回给我

Question

我试图在MainActivity中绑定服务，绑定服务受在updateTheNotification()中定义的方法MainActivity中创建的意图的约束，如下所示：

public void updateTheNotification()
    {

        Intent intentz = new Intent(context.getApplicationContext(), NotificationService.class);
        context.getApplicationContext().bindService(intentz, mConnection, Context.BIND_ABOVE_CLIENT);
        if (mBound) {
            // Call a method from the LocalService.
            // However, if this call were something that might hang, then this request should
            // occur in a separate thread to avoid slowing down the activity performance.
            mService.changeTheUI(true);
            Toast.makeText(this, "Service triggered", Toast.LENGTH_LONG).show();
        }
    }

    /** Defines callbacks for service binding, passed to bindService() */
    private ServiceConnection mConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName className,
                                       IBinder service) {
            // We've bound to LocalService, cast the IBinder and get LocalService instance
            NotificationService.LocalBinder binder = (NotificationService.LocalBinder) service;
            mService = binder.getService();
            mBound = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName arg0) {
            mBound = false;
        }
    };

updateTheNotification()由附加在通知按钮上的广播接收器onReceive方法调用。

Answer 1

方法bindService()是异步的。这意味着该方法将立即返回，即使Service尚未绑定。

当Service绑定完成后，调用ServiceConnection的onServiceConnected()方法。由于此方法是在main (UI)线程上调用的，所以当代码在主(UI)线程上调用的任何其他方法(例如，onReceive() )中执行时，不能调用该方法。

您需要将您的处理分为两部分：

1. 绑定到Service
2. 连接Service后，继续处理