android Service种简介

android Service类简介
    Service类与 Activity类的原理类似，只是Service类并不像Activity一样提供与用户交互的表示层。Service是一种后台运行的Android组件，位于android.app包下。

    当应用程序不需要在前台显示某些界面时，可以使用Service来完成，比如后台的数据计算，后台音乐播放等。

    这个小例子是同时介绍Service组件与BroadcastReceiver组件联合使用的方法，在例子中使用java代码动态注册 BroadcastReceiver 并且通过前台的用户界面控制后台服务的进行。

  运行如下







    strings.xml

<?xml version="1.0" encoding="utf-8"?><resources>    <string name="hello">请启动 Service</string>    <string name="app_name">xh_test_03</string>    <string name="myButton1">启动Service</string>    <string name="myButton2">停止Service</string></resources>

  布局文件main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:gravity="center_horizontal"    ><TextView  	android:id="@+id/myTextView"    android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:textSize="20px"    android:gravity="center_horizontal"    android:text="@string/hello"    /><Button	android:id="@+id/myButton1"	android:layout_width="wrap_content"	android:layout_height="wrap_content"	android:text="@string/myButton1"/><Button	android:id="@+id/myButton2"	android:layout_width="wrap_content"	android:layout_height="wrap_content"	android:text="@string/myButton2"/></LinearLayout>

   Service类 MyService

package xiaohang.zhimeng;import android.app.Service;import android.content.Intent;import android.os.IBinder;public class MyService extends Service {	MyThread myThread;	@Override	public IBinder onBind(Intent intent) {		return null;	}	@Override	public void onDestroy() {		myThread.flag = false;		super.onDestroy();	}	@Override	public void onStart(Intent intent, int startId) {		myThread = new MyThread();		myThread.start();		super.onStart(intent, startId);	}	class MyThread extends Thread {		boolean flag = true;		int c = 0;		@Override		public void run() {			while (flag) {				Intent i = new Intent("xiaohang.zhimeng.myThread");				i.putExtra("myThread", c);				sendBroadcast(i);				c++;				try {					// 睡眠指定毫秒数					Thread.sleep(1000);				} catch (Exception e) {					e.printStackTrace();				}			}		}	};}

Activity类 Activity01

package xiaohang.zhimeng;import android.app.Activity;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;public class Activity01 extends Activity {	Button button1;	Button button2;	TextView myTextView;	@Override	public void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.main);		button1 = (Button) this.findViewById(R.id.myButton1);		button2 = (Button) this.findViewById(R.id.myButton2);		myTextView = (TextView) this.findViewById(R.id.myTextView);		button1.setOnClickListener(new OnClickListener() {			public void onClick(View v) {				Intent i = new Intent(Activity01.this, MyService.class);				startService(i);				Toast.makeText(Activity01.this, "Service启动成功",						Toast.LENGTH_SHORT).show();			}		});		button2.setOnClickListener(new OnClickListener() {			public void onClick(View v) {				// 创建Intent				Intent i = new Intent(Activity01.this, MyService.class);				stopService(i);				Toast.makeText(Activity01.this, "Service停止成功",						Toast.LENGTH_SHORT).show();			}		});		// 创建IntentFilter过滤器		IntentFilter intentFilter = new IntentFilter(				"xiaohang.zhimeng.myThread");		MyBroadcasReceiver myBroadcasReceiver = new MyBroadcasReceiver();		registerReceiver(myBroadcasReceiver, intentFilter);	}	public class MyBroadcasReceiver extends BroadcastReceiver {		@Override		public void onReceive(Context context, Intent intent) {			// 获得Intent中的数据			Bundle myBundle = intent.getExtras();			int myInt = myBundle.getInt("myThread");			if (myInt < 10) {				myTextView.setText("后台Service运行了" + myInt + "秒");			} else {				Intent i = new Intent(Activity01.this, MyService.class);				// 停止服务				stopService(i);				myTextView.setText("后台Service在" + myInt + "秒后停止运行");			}		}	}}

 
  最后在若弱的 提醒大家一句 服务需要在 AndroidManifest.xml中声明一下



源码见附件