MessagerService总结
一、整体工程图
二、messenger_service_binding.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:padding="4dip"
android:gravity="center_horizontal"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:layout_width="match_parent" android:layout_height="wrap_content"
android:layout_weight="0"
android:paddingBottom="4dip"
android:text="@string/messenger_service_binding"/>
<Button android:id="@+id/bind"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:text="@string/bind_service">
<requestFocus />
</Button>
<Button android:id="@+id/unbind"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:text="@string/unbind_service">
</Button>
<TextView android:id="@+id/callback"
android:layout_width="match_parent" android:layout_height="wrap_content"
android:layout_weight="0"
android:gravity="center_horizontal" android:paddingTop="4dip"/>
</LinearLayout>
三、AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.jltxgcy.messengerservice"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MessengerServiceActivities"
android:label="@string/title_activity_messenger_service" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service
android:name=".MessengerService">
</service>
</application>
</manifest>
四、MessengerServiceActivities.java
package com.jltxgcy.messengerservice;
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.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MessengerServiceActivities extends Activity{
Messenger mServiceMessage = null;
boolean mIsBound;
TextView mCallbackText;
class IncomingHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MessengerService.MSG_SET_VALUE:
mCallbackText.setText("Received from service: " + msg.arg1);
break;
default:
super.handleMessage(msg);
}
}
}
final Messenger mMessenger = new Messenger(new IncomingHandler());
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
mServiceMessage = new Messenger(service);
mCallbackText.setText("Attached.");
try {
Message msg = Message.obtain(null,
MessengerService.MSG_REGISTER_CLIENT);
msg.replyTo = mMessenger;
mServiceMessage.send(msg);
msg = Message.obtain(null,
MessengerService.MSG_SET_VALUE, this.hashCode(), 0);
mServiceMessage.send(msg);
} catch (RemoteException e) {
}
}
public void onServiceDisconnected(ComponentName className) {
mServiceMessage = null;
Log.d("jltxgcy", "onServiceDisconnected");
}
};
void doBindService() {
bindService(new Intent(MessengerServiceActivities.this,
MessengerService.class), mConnection, Context.BIND_AUTO_CREATE);
mIsBound = true;
}
void doUnbindService() {
if (mIsBound) {
if (mServiceMessage != null) {
try {
Message msg = Message.obtain(null,
MessengerService.MSG_UNREGISTER_CLIENT);
msg.replyTo = mMessenger;
mServiceMessage.send(msg);
} catch (RemoteException e) {
}
}
unbindService(mConnection);
mIsBound = false;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.messenger_service_binding);
Button button = (Button)findViewById(R.id.bind);
button.setOnClickListener(mBindListener);
button = (Button)findViewById(R.id.unbind);
button.setOnClickListener(mUnbindListener);
mCallbackText = (TextView)findViewById(R.id.callback);
}
private OnClickListener mBindListener = new OnClickListener() {
public void onClick(View v) {
doBindService();
}
};
private OnClickListener mUnbindListener = new OnClickListener() {
public void onClick(View v) {
doUnbindService();
}
};
}
五、MessengerService.java
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jltxgcy.messengerservice;
import java.util.ArrayList;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;
import android.widget.Toast;
public class MessengerService extends Service {
private ArrayList<Messenger> mClients = new ArrayList<Messenger>();
private int mValue = 0;
public static final String TAG = "jltxgcy";
public static final int MSG_REGISTER_CLIENT = 1;
public static final int MSG_UNREGISTER_CLIENT = 2;
public static final int MSG_SET_VALUE = 3;
class IncomingHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_REGISTER_CLIENT:
mClients.add(msg.replyTo);
break;
case MSG_UNREGISTER_CLIENT:
mClients.remove(msg.replyTo);
break;
case MSG_SET_VALUE:
mValue = msg.arg1;
for (int i=mClients.size()-1; i>=0; i--) {
try {
mClients.get(i).send(Message.obtain(null,
MSG_SET_VALUE, mValue, 0));
} catch (RemoteException e) {
mClients.remove(i);
}
}
break;
default:
super.handleMessage(msg);
}
}
}
final Messenger mMessenger = new Messenger(new IncomingHandler());
@Override
public void onCreate() {
Log.d(TAG, "onCreate");
}
@Override
public void onDestroy() {
Log.d(TAG, "onDestroy");
}
@Override
public IBinder onBind(Intent intent) {
Log.d(TAG, "onBind");
return mMessenger.getBinder();
}
@Override
public boolean onUnbind(Intent intent) {
Log.d(TAG, "onUnbind");
return super.onUnbind(intent);
}
}
六、详解
点击Bind Service，Logcat显示如下：
Service中：final Messenger mMessenger = new Messenger(new IncomingHandler()); onBind方法中mMessenger.getBinder()
Activity中， final Messenger mMessenger = new Messenger(new IncomingHandler()); onServiceConnected中mServiceMessage = new Messenger(service);
onBind方法中返回一个IBinder对象，onServiceConnected中，通过IBinder对象获取到了Messager对象。再通过msg.replyTo建立通信。
点击Unbind Service，Logcat显示如下：
运行结果如下：
获取message的方法：
1、Message msg =new Message();
msg.arg1=x;
msg.arg2=x;
msg.obj=x;
msg.replyTo=x;
msg.what=x;
msg.setData(Bundle bundle);
2、Message msg =Messge.obtain(Handler h, int what, int arg1, int arg2, Object obj);
msg.replyTo=x;
msg.setData(Bundle bundle);