Android：IntentService：如何：将回调从 Activity 传递给 IntentService？

Question

我想将回调传递给 IntentService。这是我当前的代码：

我的回调接口

import android.os.Message;

public interface SampleCallback {

    public void doSomethingFromCurrentThread();

    public void doSomethingFromUIThread(final Message msg);
}

我的 IntentService

import android.app.IntentService;
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

public class SampleCallbackIntentService extends IntentService {
    private final String LOG_LOGCAT_TAG = "SampleCallbackIntentService";
    private final SampleCallback _callback;
    private Handler _handler;

    public SampleCallbackIntentService(String name, SampleCallback callback) {
        super(name);
        _callback = callback;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        // initialize variables for pause & resume thread
        _mPauseLock = new Object();
        _mPaused = false;
        _mFinished = false;

        // initialize handler to switch to UI/Main thread
         _handler = new Handler()
            {
                @Override
                public void handleMessage(final Message msg)
                {
                    _callback.doSomethingFromUIThread(msg);
                }
            };
    }

    private final int CALLBACK_MESSAGE = 1;
    @Override
    protected void onHandleIntent(Intent arg0) {
        Log.i(LOG_LOGCAT_TAG, "loop started");
        while (!_mFinished) {
            // do stuff here
            _callback.doSomethingFromCurrentThread();

            // process and create the result to pass
            String someResult = "some result here";
            _handler.sendMessage(_handler.obtainMessage(CALLBACK_MESSAGE, someResult));

            synchronized (_mPauseLock) {
                while (_mPaused) {
                    try {
                        Log.i(LOG_LOGCAT_TAG, "loop paused");
                        _mPauseLock.wait();
                        Log.i(LOG_LOGCAT_TAG, "loop resumed");
                    } catch (InterruptedException e) {
                        Log.e(LOG_LOGCAT_TAG, "error occured on pause", e);
                    }
                }
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                Log.e(LOG_LOGCAT_TAG, "error occured on sleep", e);
            }
        }
        Log.i(LOG_LOGCAT_TAG, "loop ended");
    }

    private Object _mPauseLock;
    private boolean _mPaused;
    private boolean _mFinished;

    /**
     * Call this on pause.
     */
    public void pause() {
        Log.i(LOG_LOGCAT_TAG, "pause() called");
        synchronized (_mPauseLock) {
            _mPaused = true;
        }
    }

    /**
     * Call this on resume.
     */
    public void resume() {
        Log.i(LOG_LOGCAT_TAG, "resume() called");
        synchronized (_mPauseLock) {
            _mPaused = false;
            _mPauseLock.notifyAll();
        }
    }
}

感谢任何有关如何传递我的回调的指导。

Answer 1

您可能正在寻找ResultReceiver。它实现了 Parcelable，因此您可以将其传递给意图服务。

很抱歉 4 年后给你答复。

Answer 2

这是一个关于从服务通知活动的好答案：Notify activity from service。至于我，Activity.createPendingResult() 是调用父活动的好方法。

这实际上不是回调，但 AFAIK 没有好的方法可以在没有绑定服务的情况下实现这样的回调。