Service 学习第二篇，我们使用BindService()来启动Service.

第一步，同样需要继承Service ，实现它必须的方法。并把这个Service注册到AndroidManifest.xml中，做为一种隐式意图，然后等待Activity的启动。

              这里IBinder onBind(Intent intent);会返回一个IBinder 对象。就是我们Acitvity 与Service 交互的对象。

BindService.java

package com.hkrt.action;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.IBinder;public class BindService extends Service {	private int count;	private boolean quit;	private MyBinder binder = new MyBinder();	public class MyBinder extends Binder {		public int getCount() {			return count;		}	}	@Override	public IBinder onBind(Intent intent) {		System.out.println("service is Binded");		return binder;	}	@Override	public void onCreate() {		System.out.println("Service is Create");		super.onCreate();		new Thread(){			@Override			 public void run(){				 while(!quit){					 try {						Thread.sleep(1000);					} catch (InterruptedException e) {						e.printStackTrace();					}					count++;				 }			 }		}.start();	}	@Override	public boolean onUnbind(Intent intent) {		System.out.println("Service is Unbind");		return true;	}	@Override	public void onDestroy() {		System.out.println("Service is Destroy");		super.onDestroy();		this.quit=true;	}}

AndroidManifest.xml

第二步：我们使用三个按钮，分别绑定Service和解除绑定，和获取Service状态。

main.xml

效果图：

第三步：关键性代码。

package com.hkrt.action;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.view.View;import android.widget.Button;import android.widget.Toast;public class ServiceDemo2Activity extends Activity {	Button bind, unBind, serviceCount;	BindService.MyBinder binder;	private ServiceConnection conn = new ServiceConnection() {		@Override		public void onServiceConnected(ComponentName name, IBinder service) {			binder = (BindService.MyBinder) service;			System.out.println("service Connected");		}		@Override		public void onServiceDisconnected(ComponentName name) {			System.out.println("service disConnectioned");		}	};	@Override	public void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.main);		bind = (Button) findViewById(R.id.bind);		unBind = (Button) findViewById(R.id.unBind);		serviceCount = (Button) findViewById(R.id.serviceCount);		final Intent intent = new Intent();		intent.setAction("com.hkrt.action.BIND_SERVICE");		bind.setOnClickListener(new View.OnClickListener() {			@Override			public void onClick(View v) {				bindService(intent, conn, Service.BIND_AUTO_CREATE);			}		});		unBind.setOnClickListener(new View.OnClickListener() {			@Override			public void onClick(View v) {				unbindService(conn);			}		});		serviceCount.setOnClickListener(new View.OnClickListener() {			@Override			public void onClick(View v) {				Toast.makeText(ServiceDemo2Activity.this,						"service的count值为" + binder.getCount(), 1).show();			}		});	}}

第四步：Service启动流程图。

Activity 与 Service 交互的结果。

Service的生命周期