android aidl空指针

有人知道为什么我总是在“myService.getMountPoint（）；”中得到空指针吗

我想我做的和互联网上的例子差不多

public class mainActivity extends Activity {
/** Called when the activity is first created. */

private IMountService myService = null;

private ServiceConnection conn = new ServiceConnection() {
    public void onServiceConnected(ComponentName name, IBinder service) {
        // TODO Auto-generated method stub

        myService = IMountService.Stub.asInterface(service);
    }

    public void onServiceDisconnected(ComponentName name) {
        // TODO Auto-generated method stub

    }
};

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    bindService(new Intent(mainActivity.this, DeviceStatusService.class), conn,
            Context.BIND_AUTO_CREATE);
    startService(new Intent(mainActivity.this, DeviceStatusService.class));
    try {
        myService.getMountPoint();
    } catch (RemoteException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

---

}

当您尝试访问服务时，该服务尚未绑定-因此在本例中引用为空。调用onServiceConnected并设置对服务的引用后，您应该执行您想要执行的操作

IMountService myService=null这就是原因。