Android学习笔记：Activity跨进程调用service。

1. 创建一个android项目如下,点击finish. 如果只是需要提供service，不需要Activity，那么可以把Create Activity的勾去掉。

 

2. 添加一java文件。

类名为:LongExistService，

superclass为:android.app.Service

 

3. 打开LongExistService.java, 点击菜单 Source-> Override/implement Method.

选中onCreate(), onDestroy(), onStart(), onStartCommand(), onUnbind().

 

4. LongExistService.java文件内容为:

 package com.pyk.les;

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

public class LongExistService extends Service {        public int getCount() {        Log.d(TAG, "LongExistService::getCount");        return 0;    }

    public String getTime() {        java.util.Date date = new java.util.Date();                Log.d(TAG, "LongExistService::onCreate");        return date.toLocaleString();    }        private final IlongExistService.Stub binder=new IlongExistService.Stub() {        public int getCount() {            Log.d(TAG, "IlongExistService::getCount");            return LongExistService.this.getCount();        }

        public String getTime() {            Log.d(TAG, "IlongExistService::getTime");            return LongExistService2.this.getTime();        }    };        final String TAG = "LongExistService";        @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) {        Log.d(TAG, "onBind");        return binder;    }}

5. 因为增加了AIDL的接口，我们需要先定义一个AIDL文件，比如IlongExistService.aidl.文件内容为:

package com.pyk.les;

 

interface IlongExistService {

int getCount();

String getTime();

}

这里必须是后缀为aidl,我试过用.java文件定义一个同样的接口，结果不能正常运行。所以这个看来是个必须起名为aidl文件的要求。

6.修改AndroidManifest.xml, 添加如下定义。

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.pyk.les2" android:versionCode="1" android:versionName="1.0"> <application android:label="Single Service">  <service android:name=".LongExistService">   <intent-filter>    <action android:name="com.pyk.les.IlongExistService"></action>   </intent-filter>  </service> </application> <uses-sdk android:minSdkVersion="8" /></manifest>

 

 

7.到此，service已经实现了。下面我们另外生成一个项目的Activity来bind这个service。

按照前面的步骤1. 我们生成一个activity。注意请用另外一个package name。Activity.java的文件内容为:

package com.pyk.client;

import com.pyk.les.IlongExistService;import android.app.Activity;import android.app.AlertDialog;import android.content.ComponentName;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 android.view.View;

public class MyActivity extends Activity { final String TAG = "MyActivity"; final Intent myIntent = new Intent("com.pyk.les.IlongExistService"); private boolean startedService = false; private IlongExistService leservice = null; ServiceConnection myServiceConnection = new ServiceConnection() {  public void onServiceConnected(ComponentName name, IBinder service) {   leservice = IlongExistService.Stub.asInterface(service);  }

  public void onServiceDisconnected(ComponentName name) {      leservice = null;  }   };    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);                setContentView(R.layout.main);        //myIntent.setClass(this, LongExistService.class);  startedService = bindService(new Intent("com.pyk.les.IlongExistService"), myServiceConnection, BIND_AUTO_CREATE);  try {            Log.i(TAG, "getCount value:" + leservice.getCount());   Log.i(TAG, "getTime value:" + leservice.getTime());        }catch (RemoteException ex)        {}    }

 @Override protected void onDestroy() {  if (startedService)  {   unbindService(myServiceConnection);  }  Log.i(TAG, "onDestroy");  super.onDestroy(); } }

8. 将IlongExistService.aidl拷贝过来，连同package的目录一起拷贝。然后刷新一下Activity项目，就能在project explorer里看到了。

 

这样，当Activity启动时，就会bind service并调用service的方法。Activity退出时会unbind。