Android中的跨進程回調

在Android應用程序開發中，可能會遇到跨進程回調問題，比如，調用一個服務，但服務是異步的，服務完成後，需要給客戶一個通知，這時就需要用到跨進程回調了。跨進程回調本質上用到了Binder機制，其過程如下：

1.定義aidl

ITest.aidl

package com.example.chirpdemo;
import com.example.chirpdemo.ITestListener;

interface ITest {
int getValue();
void setValue(int value);
void listen(ITestListener listener);
}

ITestListener.aidl

package com.example.chirpdemo;

interface ITestListener {
void onFinished(int result);
}

2.Service定義如下：

package com.example.chirpdemo;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;

public class MyService extends Service {
final private static String TAG = "MyService";

public class ServiceImpl extends ITest.Stub {
private int mValue;
private ITestListener mListener;

public ServiceImpl() {
mValue = 0;
}

@Override
public int getValue() throws RemoteException {
return mValue;
}

@Override
public void setValue(int value) throws RemoteException {
mValue = value;

if (null != mListener) {
mListener.onFinished(-1);
}
}

@Override
public void listen(ITestListener listener) throws RemoteException {
mListener = listener;
}
}

@Override
public void onCreate() {
Log.d(TAG, "onCreate");
super.onCreate();
}

@Override
public void onDestroy() {
Log.d(TAG, "onDestroy");
super.onDestroy();
}

@Override
public void onStart(Intent intent, int startId) {
Log.d(TAG, "onStart");
super.onStart(intent, startId);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d(TAG, "onStartCommand");
return super.onStartCommand(intent, flags, startId);
}

@Override
public boolean onUnbind(Intent intent) {
Log.d(TAG, "onUnbind");
return super.onUnbind(intent);
}

@Override
public void onRebind(Intent intent) {
Log.d(TAG, "onRebind");
super.onRebind(intent);
}

@Override
public IBinder onBind(Intent arg0) {
return new ServiceImpl();
}

}