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();  
                        }  
                          
                }  
              
    }  
}