Question

我正在尝试绑定到自定义服务但没有成功。

我的自定义服务

public class CustomService extends Service {
    private CustomReceiver mReceiver;
    private final CustomBinder mBinder = new CustomBinder();

    public class CustomBinder extends Binder implements ICustomService {
        // Implementation of the interface
    }

    public interface ICustomService {
        // Public interface to comunicate to the service
    }

@Override
public IBinder onBind(Intent intent) {
    Log.d("customservice", "Service bound.");
    mReceiver = intent.getParcelableExtra("receiver"); // ERROR HERE!
    return mBinder;
}

// Other methods

我的自定义接收器

public class CustomReceiver extends ResultReceiver {    
    public interface IReceiver {
        public void onReceiveResult(int resultCode, Bundle resultData);
    }

    private IReceiver mReceiver;

    public CustomReceiver(Handler handler) {
        super(handler);
    }

    public void setReceiver(IReceiver receiver) {
        mReceiver = receiver;
    }

    @Override
    protected void onReceiveResult(int resultCode, Bundle resultData) {
        if (mReceiver != null) {
            mReceiver.onReceiveResult(resultCode, resultData);
        }
    }
}

我的活动

public class MainActivity extends Activity implements CustomReceiver.IReceiver {
    IRegressiveService mService;
    CustomReceiver mReceiver;
    boolean mBound = false;

    private ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName name, IBinder service) {
            mService = (ICustomService) service;
            mBound = true;
        }

        public void onServiceDisconnected(ComponentName name) {
            mBound = false;
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        //...
        mReceiver = new CustomReceiver(new Handler());
        mReceiver.setReceiver(this);

        Intent bindServiceIntent = new Intent(this, CustomService.class);
        bindServiceIntent.putExtra("receiver", mReceiver);
        bindService(bindServiceIntent, mConnection, Context.BIND_AUTO_CREATE);
    }

    public void onReceiveResult(int resultCode, Bundle resultData) {
        //...
    }

    //...
}

Stacktrace（不完整）

04-29 20:23:55.851: E/AndroidRuntime(690): FATAL EXCEPTION: main
04-29 20:23:55.851: E/AndroidRuntime(690): java.lang.RuntimeException: Unable to bind to service [package].CustomService@44f38cd8 with Intent { cmp=[package].CustomService (has extras) }: java.lang.ClassCastException: android.os.ResultReceiver
04-29 20:23:55.851: E/AndroidRuntime(690): at android.app.ActivityThread.handleBindService(ActivityThread.java:2996)
[...]
04-29 20:23:55.851: E/AndroidRuntime(690): Caused by: java.lang.ClassCastException: android.os.ResultReceiver
04-29 20:23:55.851: E/AndroidRuntime(690): at [package].CustomService.onBind(CustomService.java:37)
04-29 20:23:55.851: E/AndroidRuntime(690): at android.app.ActivityThread.handleBindService(ActivityThread.java:2983)
[...]

简而言之

在Activity中，我使用＆＃34; receiver＆＃34;将CustomReceiver（一个ResultReceiver子类）的实例传递给服务。键。但是当我尝试恢复此对象时，在服务中，ClassCastException被引发。为什么？我该如何解决这个问题？

我的目标是API级别8。

我在其他任何SO问题中都找不到这种行为。

Answer 1

我刚检查了我的代码。尝试在mReceiver作为基础Service声明ResultReceiver，如下所示......

public class CustomService extends Service {
    private ResultReceiver mReceiver;
    ...
}

这就是我的工作，当我从ClassCastException获取接收器时，Service中没有Intent（我的也是自定义ResultReceiver）

Answer 2

BroadcastReceiver（默认情况下）不是Parcelable。所以你期望得到一个ClassCastException。如果需要传递特定实例，请向服务添加setter方法，然后使用该对象从ServiceConnection实现中调用该方法。

Answer 3

我与ClassCastException有完全相同的问题，这对我没有任何意义。我在这里看到了关于将mReceiver设置为仅使用ResultReceiver而不是服务中的CustomReceiver的答案。我做到了但仍然遇到了同样的错误，但我注意到我的import语句不一样。

在我的MainActivity中，我导入了声明：

import android.support.v4.os.ResultReceiver;

然而，在我的服务中，我导入了声明：

import android.os.ResultReceiver;

我确保在我的服务和我使用的MainActivity中使用了以下内容：

import android.support.v4.os.ResultReceiver;

它现在正常运作！希望这有助于某人！

我也迟到了几年..

如何正确地将ResultReceiver子类发送到服务？

3 个答案: