return instance;
}
//退出栈顶Activity
public void popActivity(Activity activity) {
if (activity != null) {
//在从自定义集合中取出当前Activity时，也进行了Activity的关闭操作
activity.finish();
activityStack.remove(activity);
activity = null;
}
}
//获得当前栈顶Activity
public Activity currentActivity() {
Activity activity = null;
if(!activityStack.empty())
activity= activityStack.lastElement();
return activity;
}
//将当前Activity推入栈中
public void pushActivity(Activity activity) {
if (activityStack == null) {
activityStack = new Stack();
}
activityStack.add(activity);
}
//退出栈中所有Activity
public void popAllActivityExceptOne(Class cls) {
while (true) {
Activity activity = currentActivity();
if (activity &
