Android學習筆記：Activity跨進程調用service。

1. 建立一個android項目如下,點擊finish. 如果只是需要提供service，不需要Activity，那麼可以把Create Activity的勾去掉。

 

2. 添加一java檔案。

類名為:LongExistService，

superclass為:android.app.Service

 

3. 開啟LongExistService.java, 點擊菜單 Source-> Override/implement Method.

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

 

4. LongExistService.java檔案內容為:

 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. 因為增加了AIDL的介面，我們需要先定義一個AIDL檔案，比如IlongExistService.aidl.檔案內容為:

package com.pyk.les;

 

interface IlongExistService {

int getCount();

String getTime();

}

這裡必須是尾碼為aidl,我試過用.java檔案定義一個同樣的介面，結果不能正常運行。所以這個看來是個必須起名為aidl檔案的要求。

6.修改AndroidManifest.xml, 添加如下定義。

<?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已經實現了。下面我們另外產生一個項目的Activity來bind這個service。

按照前面的步驟1. 我們產生一個activity。注意請用另外一個package name。Activity.java的檔案內容為:

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. 將IlongExistService.aidl拷貝過來，連同package的目錄一起拷貝。然後重新整理一下Activity項目，就能在project explorer裡看到了。

 

這樣，當Activity啟動時，就會bind service並調用service的方法。Activity退出時會unbind。