Android Service Android Service(不和用户交互应用组件)案例分析

<?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"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Welcome to my blog!"
android:textSize="16sp"/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="音乐播放服务"/>
<Button
android:id="@+id/startMusic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开启音乐播放服务"/>
<Button
android:id="@+id/stopMusic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="停止音乐播放服务"/>
<Button
android:id="@+id/bindMusic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="绑定音乐播放服务"/>
<Button
android:id="@+id/unbindMusic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="解除 ——绑定音乐播放服务"/>
</LinearLayout>

package com.example.musicservice;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;
public class MusicService extends Service {
//为日志工具设置标签
private static String TAG = "MusicService";
//定义音乐播放器变量
private MediaPlayer mPlayer;
//该服务不存在需要被创建时被调用，不管startService()还是bindService()都会启动时调用该方法
@Override
public void onCreate() {
Toast.makeText(this, "MusicSevice onCreate()"
, Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicSerice onCreate()");
mPlayer = MediaPlayer.create(getApplicationContext(), R.raw.music);
//设置可以重复播放
mPlayer.setLooping(true);
super.onCreate();
}
@Override
public void onStart(Intent intent, int startId) {
Toast.makeText(this, "MusicSevice onStart()"
, Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicSerice onStart()");
mPlayer.start();
super.onStart(intent, startId);
}
@Override
public void onDestroy() {
Toast.makeText(this, "MusicSevice onDestroy()"
, Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicSerice onDestroy()");
mPlayer.stop();
super.onDestroy();
}
//其他对象通过bindService 方法通知该Service时该方法被调用
@Override
public IBinder onBind(Intent intent) {
Toast.makeText(this, "MusicSevice onBind()"
, Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicSerice onBind()");
mPlayer.start();
return null;
}
//其它对象通过unbindService方法通知该Service时该方法被调用
@Override
public boolean onUnbind(Intent intent) {
Toast.makeText(this, "MusicSevice onUnbind()"
, Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicSerice onUnbind()");
mPlayer.stop();
return super.onUnbind(intent);
}
}

package com.example.musicservice;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.view.View.OnClickListener;
public class MainActivity extends Activity {
//为日志工具设置标签
private static String TAG = "MusicService";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//输出Toast消息和日志记录
Toast.makeText(this, "MusicServiceActivity",
Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicServiceActivity");
initlizeViews();
}
private void initlizeViews(){
Button btnStart = (Button)findViewById(R.id.startMusic);
Button btnStop = (Button)findViewById(R.id.stopMusic);
Button btnBind = (Button)findViewById(R.id.bindMusic);
Button btnUnbind = (Button)findViewById(R.id.unbindMusic);
//定义点击监听器
OnClickListener ocl = new OnClickListener() {
@Override
public void onClick(View v) {
//显示指定 intent所指的对象是个 service
Intent intent = new Intent(MainActivity.this,MusicService.class);
switch(v.getId()){
case R.id.startMusic:
//开始服务
startService(intent);
break;
case R.id.stopMusic:
//停止服务
stopService(intent);
break;
case R.id.bindMusic:
//绑定服务
bindService(intent, conn, Context.BIND_AUTO_CREATE);
break;
case R.id.unbindMusic:
//解绑服务
unbindService(conn);
break;
}
}
};
//绑定点击监听
btnStart.setOnClickListener(ocl);
btnStop.setOnClickListener(ocl);
btnBind.setOnClickListener(ocl);
btnUnbind.setOnClickListener(ocl);
}
//定义服务链接对象
final ServiceConnection conn = new ServiceConnection() {
@Override
public void onServiceDisconnected(ComponentName name) {
Toast.makeText(MainActivity.this, "MusicServiceActivity onSeviceDisconnected"
, Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicServiceActivity onSeviceDisconnected");
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Toast.makeText(MainActivity.this, "MusicServiceActivity onServiceConnected"
,Toast.LENGTH_SHORT).show();
Log.e(TAG, "MusicServiceActivity onServiceConnected");
}
};
}