android Service的用法

Service是后台运行的服务，启动Service可以StartService或者bindservice

看看Service的生命周期。

当调用StartService时，先走oncreat方法，在走onstart方法。当stopservice时，走ondestory方法。

可以绑定一个Service，让它在后台执行，比方说后台播放歌曲等就是这样的。

当绑定一个Service时，用bindService方法，这时先走oncreate方法，在走onbind方法。当想停止Service时，用onunbindService方法，这时先走onUnbind方法，在走ondestory方法。

上代码：

package com.android.test;

import android.app.Service;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.IBinder;

public class TestService extends Service {

	@Override
	public IBinder onBind(Intent arg0) {
		// TODO Auto-generated method stub
		System.out.println("onBind");
		return null;
	}

	@Override
	public void onCreate() {
		// TODO Auto-generated method stub
		System.out.println("onCreate");
		super.onCreate();
	}
	
	@Override
	public void onStart(Intent intent, int startId) {
		// TODO Auto-generated method stub
		System.out.println("onStart");
		super.onStart(intent, startId);
	}
	
	@Override
	public void onDestroy() {
		// TODO Auto-generated method stub
		System.out.println("onDestroy");
		super.onDestroy();
	}
	
	@Override
	public boolean onUnbind(Intent intent) {
		// TODO Auto-generated method stub
		System.out.println("onUnbind");
		return super.onUnbind(intent);
	}
	
	@Override
	public void onRebind(Intent intent) {
		// TODO Auto-generated method stub
		System.out.println("onRebind");
		super.onRebind(intent);
	}
}

上面这个是Service代码，下面这个是Activity的代码：

package com.android.test;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class TestActivity extends Activity implements OnClickListener {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button button1 = (Button) findViewById(R.id.button1);
        Button button2 = (Button) findViewById(R.id.button2);
        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
    }

    public void onClick(View arg0) {
        // TODO Auto-generated method stub
        Intent intent = new Intent();
        intent.setAction("com.android.testservice");
        switch(arg0.getId()) {
        case R.id.button1:
//            startService(intent);
            bindService(intent, sc, BIND_AUTO_CREATE);
            break;
        case R.id.button2:
//            stopService(intent);
            unbindService(sc);
            break;
        }
    }
    
    ServiceConnection sc = new ServiceConnection() {

        public void onServiceConnected(ComponentName arg0, IBinder arg1) {
            System.out.println("onServiceConnected");
        }

        public void onServiceDisconnected(ComponentName arg0) {
            System.out.println("onServiceDisconnected");
        }
        
    };
}

哦，对了还要记得在manifest里面注册呢。

    <service android:name=".TestService">
        <intent-filter>
            <action android:name="com.android.testservice"/>
        </intent-filter>
    </service>

当调用startService方法的时候，打印出来的log是：

　　oncreate

　　onstart

当调用stopService方法的时候，打印出来的log是：

　　ondestory

当调用bindService和unbindServide方法时，打印出来的log是：

11-25 12:30:47.837: INFO/System.out(335): onCreate
11-25 12:30:47.887: INFO/System.out(335): onBind
11-25 12:30:49.838: INFO/System.out(335): onUnbind
11-25 12:30:49.872: INFO/System.out(335): onDestroy