android退出所有Actiivty的实例方法

import java.util.ArrayList; 
import java.util.List; 
import android.app.Activity; 
import android.app.Application; 
 
public class MyApplication extends Application { 
	private List<Activity> activityList = new ArrayList<Activity>(); 
	private static MyApplication instance; 
 
	private MyApplication() { 
 
	} 
 
	// 单列模式获取唯一MyApplication的实例 
	static MyApplication getinstance() { 
		if (instance == null) { 
			instance = new MyApplication(); 
		} 
		return instance; 
	} 
 
	// 添加Activity到容器中 
	public void addActivity(Activity acivity) { 
		activityList.add(acivity); 
	} 
 
	// 遍历所有的Activity并fanish 
	public void closeAllActiivty() { 
		for (int i = 0; i < activityList.size(); i++) { 
			Activity activity = activityList.get(i); 
			activity.finish(); 
		} 
		System.exit(0); 
	} 
 
} 
 
在Activity 的Oncreate（）的方法中执行： 
	MyApplication.getinstance().addActivity(FirstActivity.this); 
 
在退出所有的Activity执行： 
MyApplication.getinstance().closeAllActiivty();