Android之service实例

第一步:新建一个Android工程，我这里命名为ServiceDemo.

第二步:修改main.xml代码，我这里增加了四个按钮,代码如下:

 

<?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:id="@+id/text"  
	    android:layout_width="fill_parent" 
	    android:layout_height="wrap_content" 
	    android:text="@string/hello"
	    />
	<Button
		android:id="@+id/startservice"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:text="startService"
	/>
	<Button
		android:id="@+id/stopservice"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:text="stopService"
	/>
	<Button
		android:id="@+id/bindservice"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:text="bindService"
	/>
	<Button
		android:id="@+id/unbindservice"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:text="unbindService"
	/>
</LinearLayout>

 

第三步:新建一个Service，命名为MyService.java代码如下:

 

package com.tutor.servicedemo;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.text.format.Time;
import android.util.Log;
public class MyService extends Service {
	//定义个一个Tag标签
	private static final String TAG = "MyService";
	//这里定义吧一个Binder类，用在onBind()有方法里，这样Activity那边可以获取到
	private MyBinder mBinder = new MyBinder();
	@Override
	public IBinder onBind(Intent intent) {
		Log.e(TAG, "start IBinder~~~");
		return mBinder;
	}
	@Override
	public void onCreate() {
		Log.e(TAG, "start onCreate~~~");
		super.onCreate();
	}
	
	@Override
	public void onStart(Intent intent, int startId) {
		Log.e(TAG, "start onStart~~~");
		super.onStart(intent, startId);	
	}
	
	@Override
	public void onDestroy() {
		Log.e(TAG, "start onDestroy~~~");
		super.onDestroy();
	}
	
	
	@Override
	public boolean onUnbind(Intent intent) {
		Log.e(TAG, "start onUnbind~~~");
		return super.onUnbind(intent);
	}
	
	//这里我写了一个获取当前时间的函数，不过没有格式化就先这么着吧
	public String getSystemTime(){
		
		Time t = new Time();
		t.setToNow();
		return t.toString();
	}
	
	public class MyBinder extends Binder{
		MyService getService()
		{
			return MyService.this;
		}
	}
}

 

第四步:修改ServiceDemo.java，代码如下:

package com.tutor.servicedemo;
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.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class ServiceDemo extends Activity implements OnClickListener{
   
	private MyService  mMyService;
	private TextView mTextView;
	private Button startServiceButton;
	private Button stopServiceButton;
	private Button bindServiceButton;
	private Button unbindServiceButton;
	private Context mContext;
	
	//这里需要用到ServiceConnection在Context.bindService和context.unBindService()里用到
	private ServiceConnection mServiceConnection = new ServiceConnection() {
		//当我bindService时，让TextView显示MyService里getSystemTime()方法的返回值	
		public void onServiceConnected(ComponentName name, IBinder service) {
			// TODO Auto-generated method stub
			mMyService = ((MyService.MyBinder)service).getService();
			mTextView.setText("I am frome Service :" + mMyService.getSystemTime());
		}
		
		public void onServiceDisconnected(ComponentName name) {
			// TODO Auto-generated method stub
			
		}
	};
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setupViews();
    }
    
    public void setupViews(){
    
    	mContext = ServiceDemo.this;
    	mTextView = (TextView)findViewById(R.id.text);
    	
    	
    	
    	startServiceButton = (Button)findViewById(R.id.startservice);
    	stopServiceButton = (Button)findViewById(R.id.stopservice);
    	bindServiceButton = (Button)findViewById(R.id.bindservice);
    	unbindServiceButton = (Button)findViewById(R.id.unbindservice);
    	
    	startServiceButton.setOnClickListener(this);
    	stopServiceButton.setOnClickListener(this);
    	bindServiceButton.setOnClickListener(this);
    	unbindServiceButton.setOnClickListener(this);
    }
   
	public void onClick(View v) {
		// TODO Auto-generated method stub
		if(v == startServiceButton){
			Intent i  = new Intent();
			i.setClass(ServiceDemo.this, MyService.class);
			mContext.startService(i);
		}else if(v == stopServiceButton){
			Intent i  = new Intent();
			i.setClass(ServiceDemo.this, MyService.class);
			mContext.stopService(i);
		}else if(v == bindServiceButton){
			Intent i  = new Intent();
			i.setClass(ServiceDemo.this, MyService.class);
			mContext.bindService(i, mServiceConnection, BIND_AUTO_CREATE);
		}else{
			mContext.unbindService(mServiceConnection);
		}
	}
	
	
	
}

 第五步:修改AndroidManifest.xml代码(将我们新建的MyService注册进去如下代码第14行:) 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.tutor.servicedemo"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".ServiceDemo"
                  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" android:exported="true"></service>
    </application>
    <uses-sdk android:minSdkVersion="7" />
</manifest>&nbsp;

 

第六步:执行上述工程,效果图如下:

 

点击startServie按钮时先后执行了Service中onCreate()->onStart()这两个方法，打开Logcat视窗效果如下图:

我们这时可以按HOME键进入Settings(设置)->Applications(应用）->Running Services(正在运行的服务）看一下我们新启动了一个服务，效果如下:

点击stopService按钮时，Service则执行了onDestroy()方法，效果图如下所示:

这时候我们再次点击startService按钮，然后点击bindService按钮(通常bindService都是bind已经启动的Service)，我们看一下Service执行了IBinder()方法，以及TextView的值也有所变化了，如下两张图所示:

最后点击unbindService按钮，则Service执行了onUnbind()方法，如下图所示: