在iOS开 发中，对UITextField进行编辑的时候键盘会自己弹出来。在编辑完成的时候，需要将键盘隐藏掉。隐藏键盘有很多种实现方法，最常见的是把 TextField的firstResponder resign掉。即[textField resignFirstResponder]。本文介绍的是如何在键盘显示的时候，点击屏幕除了键盘以外的任何地方，将键盘隐藏
基本思想如下:
1. 在ViewController载入的时候，将键盘显示和消失的Notification添加到self.view里。
2. 分别在键盘显示和消失时添加和删除TapGestureRecognizer
示例代码如下:
UIViewController的源代码里:
- (void)viewDidLoad
{
[super viewDidLoad];
[self setUpForDismissKeyboard];
}
- (void)setUpForDismissKeyboard {
NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
UITapGestureRecognizer *singleTapGR =
[[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(tapAnywhereToDismissKeyboard:)];
NSOperationQueue *mainQuene =[NSOperationQueue mainQueue];
[nc addObserverForName:UIKeyboardWillShowNotification
object:nil
queue:mainQuene
usingBlock:^(NSNotification *note){
[self.view addGestureRecognizer:singleTapGR];
}];
[nc addObserverForName:UIKeyboardWillHideNotification
object:nil
queue:mainQuene
usingBlock:^(NSNotification *note){
[self.view removeGestureRecognizer:singleTapGR];
}];
}
- (void)tapAnywhereToDismissKeyboard:(UIGestureRecognizer *)gestureRecognizer {
//此method会将self.view里所有的subview的first responder都resign掉
[self.view endEditing:YES];
}