Android学习之Service(1)--->Started方式

界面退出后进程程序还在运行，不会被杀死，如音乐播发器、后台下载等

注：本文只讨论Started方式

main.xml代码分析

<?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"
    >
    <Button
        android:id="@+id/btnStartService"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Start Service"
        />
    <Button
        android:id="@+id/btnStopService"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Stop Service"
        />
</LinearLayout>

创建一个class类ExampleService.java

package com.szy.service;

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

public class ExampleService extends Service
{
    private static final String TAG="ExampleService";

    @Override
    public void onCreate()
    {
        Log.i(TAG, "ExampleService-->onCreate");
        super.onCreate();
    }

    @Override
    public void onStart(Intent intent, int startId)
    {
        // TODO Auto-generated method stub
        super.onStart(intent, startId);
    }

    @Override
    public void onDestroy()
    {
        Log.i(TAG, "ExampleService-->onDestroy");
        super.onDestroy();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        Log.i(TAG, "ExampleService-->onStartCommand");
        return START_NOT_STICKY;
    }

    @Override
    public IBinder onBind(Intent intent)
    {
        return null;
    }

}

主对象类MainActivity.java

package com.szy.service;

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

public class MainActivity extends Activity
{
    private Button btnStartService;
    private Button btnStopService;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnStartService = (Button) findViewById(R.id.btnStartService);
        btnStopService = (Button) findViewById(R.id.btnStopService);
        btnStartService.setOnClickListener(listener);
        btnStopService.setOnClickListener(listener);
    }

    private OnClickListener listener=new OnClickListener()
    {

        public void onClick(View v)
        {
            Intent intent=new Intent(MainActivity.this, ExampleService.class);
            switch (v.getId())
            {
            case R.id.btnStartService:
                startService(intent);
                break;
            case R.id.btnStopService:
                stopService(intent);
                break;
            default:
                break;
            }

        }
    };
}

在AndroidManifest.xml定义一下

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.szy.service"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name=".ExampleService" />

    </application>
</manifest>