Ios ipad如何知道键盘被隐藏了

我正在构建一个ipad应用程序

它有一些文本字段，点击时会移动到键盘上方

NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
[center addObserver:self selector:@selector(didShow) name:UIKeyboardDidShowNotification object:nil];
[center addObserver:self selector:@selector(didHide) name:UIKeyboardWillHideNotification object:nil];

//Resize your views in the below methods
- (void)didShow
{

}

- (void)didHide
{

}

如果点击“计算”按钮，键盘和视图将向下

但如果用户在ipad上点击隐藏键盘[键盘右下角键]

我的视野仍然很高

那么，我如何通过编程知道“隐藏键盘”已被点击

---

非常感谢

您应该使用通知中心来跟踪键盘

NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
[center addObserver:self selector:@selector(didShow) name:UIKeyboardDidShowNotification object:nil];
[center addObserver:self selector:@selector(didHide) name:UIKeyboardWillHideNotification object:nil];

//Resize your views in the below methods
- (void)didShow
{

}

- (void)didHide
{

}