android判断一个Activity是否处于栈顶

 /**
     *
     * 判断某activity是否处于栈顶
     * @return  true在栈顶 false不在栈顶
     */
    public static boolean isActivityTop(Class cls,Context context){
        ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        String name = manager.getRunningTasks(1).get(0).topActivity.getClassName();
        return name.equals(cls.getName());
    }