安卓开发service

如果把Activity比喻为前台程序，那么service可以看做是一个后台程序。Service跟Activity一样也由Intent调用。

在工程里想要添加一个Service，先新建继承Service的类，然后到AndroidManifest.xml -> Application 

中的Service标签中添加。

如下：

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

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<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=".MyService">
<intent-filter>
<action android:name="" />
</intent-filter>
</service>
</application>

</manifest>

其中，第一个name是service的位置，包括完整的包名和service名，如果包名就是你定义的程序包名，也就是和gen目录下那个包的名字一样的话，直接".service名"就可以了。第二个name是你调用service时intent.setAction();中的参数，这个可以自己随便定义。

代码如下：

activity_main.xml:

<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:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/btnStartMyService"
android:text="StartMyService">
</Button>
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/btnStopMyService"
android:text="StopMyService">
</Button>
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/btnBindMyService"
android:text="BindMyService">
</Button>
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/btnUnbindMyService"
android:text="UnbindMyService">
</Button>
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/btnExit"
android:text="退出程序">
</Button>
</LinearLayout>

MyService.java:

package com.example.service;

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

public class MyService extends Service {
static public String ServiceState="";
@Override
public IBinder onBind(Intent arg0) {
Log.e("Service", "onBind");
ServiceState="onBind";
return null;
}
@Override
public boolean onUnbind(Intent intent){
super.onUnbind(intent);
Log.e("Service", "onUnbind");
ServiceState="onUnbind";
return false;

}
@Override
public void onCreate(){
super.onCreate();
Log.e("Service", "onCreate");
ServiceState="onCreate";
}
@Override
public void onDestroy(){
super.onDestroy();
Log.e("Service", "onDestroy");
ServiceState="onDestroy";
}
@Override
public void onStart(Intent intent,int startid){
super.onStart(intent, startid);
Log.e("Service", "onStart");
ServiceState="onStart";
}

}

MainActivity.java:

package com.example.service;

import android.app.Activity;
import android.app.Service;
import android.content.ComponentName;
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;

public class MainActivity extends Activity {
Button btnStartMyService,btnStopMyService,btnBindMyService,btnUnbindMyService,btnExit;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnStartMyService=(Button)this.findViewById(R.id.btnStartMyService);
btnStartMyService.setOnClickListener(new ClickEvent());

btnStopMyService=(Button)this.findViewById(R.id.btnStopMyService);
btnStopMyService.setOnClickListener(new ClickEvent());

btnBindMyService=(Button)this.findViewById(R.id.btnBindMyService);
btnBindMyService.setOnClickListener(new ClickEvent());

btnUnbindMyService=(Button)this.findViewById(R.id.btnUnbindMyService);
btnUnbindMyService.setOnClickListener(new ClickEvent());

btnExit=(Button)this.findViewById(R.id.btnExit);
btnExit.setOnClickListener(new ClickEvent());
}
@Override
public void onDestroy()
{
super.onDestroy();
Log.e("Activity","onDestroy");
}

private ServiceConnection _connection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName arg0, IBinder arg1) {
// TODO Auto-generated method stub
}

@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub
}
};
class ClickEvent implements View.OnClickListener{

@Override
public void onClick(View v) {
Intent intent=new Intent(MainActivity.this,MyService.class);
if(v==btnStartMyService){
MainActivity.this.startService(intent);
}
else if(v==btnStopMyService){
MainActivity.this.stopService(intent);
}
else if(v==btnBindMyService){
MainActivity.this.bindService(intent, _connection, Service.BIND_AUTO_CREATE);
}
else if(v==btnUnbindMyService){
if(MyService.ServiceState=="onBind")//Service绑定了之后才能解绑
MainActivity.this.unbindService(_connection);
}
else if(v==btnExit)
{
MainActivity.this.finish();
}

}

}
}