AndroidのActivity之退出返回栈(二)

package cn.jju.vo;

import java.util.LinkedList;
import java.util.List;

import cn.jju.edu.main.MainActivity;

import android.app.Activity;
import android.app.Application;

public class MyApplication extends Application {

private List<Activity> listActivity = new LinkedList<Activity>();
private static MyApplication instance;
private MyApplication(){}
//单列模式获取唯一的MyApplication实例
public static MyApplication getInstance(){
if(null == instance){
instance = new MyApplication();
}
return instance;
}
//添加Activity到容器
public void addActivity(Activity activity){
listActivity.add(activity);
}
//遍历所有Activity并且finish
public void exit(){
for(Activity act:listActivity){
if(!act.isFinishing()){
act.finish();
}
}
System.exit(0);
}

public void finishActivity(){
for(Activity act:listActivity){
if(!act.isFinishing()){
act.finish();
}
}
}

//获取列表的长度
public int getLength(){
return listActivity.size();
}
public Activity getActivity(int location){
return listActivity.get(location);
}
}