Android学习笔记，第九周

Messenger案例

一个简单的Messenger案例，可以用来进程间通信。

package org.mobiletrain.messenger;
 2 
 3 import android.app.Activity;
 4 
 5 public class MainActivity extends Activity {
 6 
 7     private Button bind;
 8     private Button send;
 9 
10     private Messenger messenger;
11     private Messenger sendMessenger;
12 
13     Handler handler = new Handler() {
14         @Override
15         public void handleMessage(Message msg) {
16             System.out.println("acitivty handler");
17             super.handleMessage(msg);
18         }
19     };
20 
21     ServiceConnection conn = new ServiceConnection() {
22         @Override
23         public void onServiceConnected(ComponentName name, IBinder binder) {
24             messenger = new Messenger(binder);
25         }
26 
27         @Override
28         public void onServiceDisconnected(ComponentName arg0) {
29 
30         }
31     };
32 
33     @Override
34     protected void onCreate(Bundle savedInstanceState) {
35         super.onCreate(savedInstanceState);
36         setContentView(R.layout.activity_main);
37 
38         bind = (Button) findViewById(R.id.bindButton);
39         send = (Button) findViewById(R.id.sendButton);
40 
41         bind.setOnClickListener(new OnClickListener() {
42             @Override
43             public void onClick(View v) {
44                 Intent intent = new Intent();
45                 intent.setClass(MainActivity.this, MessengerService.class);
46                 bindService(intent, conn, Context.BIND_AUTO_CREATE);
47             }
48         });
49 
50         send.setOnClickListener(new OnClickListener() {
51             @Override
52             public void onClick(View v) {
53                 sendMessenger = new Messenger(handler);
54                 Message msg = Message.obtain(null, 0);
55                 msg.replyTo = sendMessenger;
56                 try {
57                     messenger.send(msg);
58                 } catch (RemoteException e) {
59                     e.printStackTrace();
60                 }
61             }
62         });
63     }
64 
65 }

布局文件如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 2 xmlns:tools="http://schemas.android.com/tools" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 tools:context=".MainActivity" >
 6 
 7     <Button  8 android:id="@+id/bindButton" 9 android:layout_width="wrap_content" 10 android:layout_height="wrap_content" 11 android:layout_alignParentTop="true" 12 android:layout_centerHorizontal="true" 13 android:layout_marginTop="149dp" 14 android:text="bind" />
15     
16     <Button 17 android:id="@+id/sendButton" 18 android:layout_width="wrap_content" 19 android:layout_height="wrap_content" 20 android:layout_below="@id/bindButton" 21 android:layout_alignLeft="@id/bindButton" 22 android:text="send" 23 />
24 
25 </RelativeLayout>

服务中代码如下：

package org.mobiletrain.messenger;
 2 
 3 import android.app.Service;
 4 
 5 public class MessengerService extends Service {
 6 
 7     Messenger replyMessenger = null;
 8     Messenger messenger = null;
 9 
10     @Override
11     public IBinder onBind(Intent arg0) {
12         messenger = new Messenger(handler);
13         return messenger.getBinder();
14     }
15 
16     Handler handler = new Handler() {
17         @Override
18         public void handleMessage(Message msg) {
19             if (msg.what == 0) {
20                 replyMessenger = msg.replyTo;
21                 new MyThread().start();
22             }
23             super.handleMessage(msg);
24         }
25 
26     };
27 
28     class MyThread extends Thread {
29         public void run() {
30             System.out.println("Thread start");
31             try {
32                 Thread.sleep(5 * 1000);
33             } catch (InterruptedException e) {
34                 e.printStackTrace();
35             }
36             System.out.println("Thread finish");
37             Message msg = Message.obtain(null, 0);
38             try {
39                 replyMessenger.send(msg);
40             } catch (RemoteException e) {
41                 e.printStackTrace();
42             }
43         }
44     }
45 }