在application中一键退出

在其他activity中调用添加方法

public static PetApplication instance;

private static List<Activity> activityList;

public static PetApplication getInstance()
{
if(null == instance)
{
instance = new PetApplication();
activityList = new ArrayList<Activity>();
}
return instance; 


}


    public void addActivity(Activity a){
    activityList.add(a);
    }


public void exit()
{


for(Activity activity:activityList)
{
activity.finish();
}


System.exit(0);


}