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();
                        }  

                }  

    }
}