使用android中的AIDL让Service与Activity通信(service回调activity)

这几天搞了搞AIDL,终于弄明白了在AIDL中让Service调用Activity的方法

代码:

首先建立一个ICallback.aidl文件,作为Activity中的回调方法

package com.zhang.test.service;

interface ICallback {

void showResult(int result);

}

然后再建立一个IService.aidl用来在Activity中接收Service回调,以及在Service中onBind时返回的Binder

注意:aidl中import不能写com.xxx.*,要写全类的路径

package com.zhang.test.service;

import com.zhang.test.service.ICallback;

interface IService {

void registerCallback(ICallback cb);

void unregisterCallback(ICallback cb);

}

复制代码
接下来是service:

MainService.java

package com.zhang.test.service;

import android.app.Service;

import android.content.Intent;

import android.os.Handler;

import android.os.IBinder;

import android.os.Message;

import android.os.RemoteCallbackList;

import android.os.RemoteException;

import android.util.Log;

public class MainService extends Service {

private static final String TAG = "MainService";

private RemoteCallbackList<icallback> mCallbacks = new RemoteCallbackList<icallback>();

private IService.Stub mBinder = new IService.Stub() {

@Override

public void unregisterCallback(ICallback cb){

if(cb != null) {

mCallbacks.unregister(cb);

}

}

@Override

public void registerCallback(ICallback cb){

if(cb != null) {

mCallbacks.register(cb);

}

}

};

@Override

public IBinder onBind(Intent intent) {

Log.d(TAG, "onBind");

return mBinder;

}

@Override

public void onCreate() {

Log.d(TAG, "onCreate");

//这里不知道为什么,直接使用callback方法回调showResult

//mCallbacks.beginBroadcast()是0,需要用handler延迟1000毫秒

//也许是在activity中binService太耗时的原因?

mHandler.sendEmptyMessageDelayed(0, 1000);

super.onCreate();

}

@Override

public void onDestroy() {

mHandler.removeMessages(0);

mCallbacks.kill();

super.onDestroy();

}

private void callBack() {

int N = mCallbacks.beginBroadcast();

try {

for (int i = 0; i < N; i++) {

mCallbacks.getBroadcastItem(i).showResult(i);

}

} catch (RemoteException e) {

Log.e(TAG, "", e);

}

mCallbacks.finishBroadcast();

}

private Handler mHandler = new Handler() {

@Override

public void handleMessage(Message msg) {

callBack();

super.handleMessage(msg);

}

};

}

</icallback></icallback>

复制代码
然后是activity:

package com.zhang.test;

import android.app.Activity;

import android.content.ComponentName;

import android.content.Context;

import android.content.Intent;

import android.content.ServiceConnection;

import android.os.Bundle;

import android.os.IBinder;

import android.os.RemoteException;

import android.util.Log;

import com.zhang.test.service.ICallback;

import com.zhang.test.service.IService;

import com.zhang.test.service.MainService;

public class MainActivity extends Activity {

private static final String TAG = "MainActivity";

private IService mService;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

Intent i = new Intent(this, MainService.class);

bindService(i, mConnection, Context.BIND_AUTO_CREATE);

}

@Override

protected void onDestroy() {

if(mService!=null){

try {

mService.unregisterCallback(mCallback);

} catch (RemoteException e) {

Log.e(TAG, "", e);

}

}

//destroy的时候不要忘记unbindService

unbindService(mConnection);

super.onDestroy();

}

/**

* service的回调方法

*/

private ICallback.Stub mCallback = new ICallback.Stub() {

@Override

public void showResult(int result) {

Log.d(TAG, " result : " + result);

}

};

/**

* 注册connection

*/

private ServiceConnection mConnection = new ServiceConnection() {

@Override

public void onServiceDisconnected(ComponentName name) {

Log.d(TAG, "onServiceDisconnected");

mService = null;

}

@Override

public void onServiceConnected(ComponentName name, IBinder service) {

Log.d(TAG, "onServiceConnected");

mService = IService.Stub.asInterface(service);

try {

mService.registerCallback(mCallback);

} catch (RemoteException e) {

Log.e(TAG, "", e);

}

}

};

}

最后不要忘记在manifest中加上service标记:

<service android:name=".service.MainService">

</service>

运行程序,查看Logcat

结果如下:

总结:

通过aidl总算实现了Service与Activity的通信,写起来麻烦点,使用诸如ContentProvider,Broadcast等也可以实现.

这样做很像是在使用MVC设计模式(Activity负责View,Service以及其他类负责 Model,aidl(ServiceConnection)负责Controller),其实我对于aidl也是一知半解- -,明天研究下如何让activity去调用service中的方法.