UI键盘通知

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic,strong) UITextField *tf;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

_tf = [[UITextField alloc]initWithFrame:CGRectMake(10, self.view.bounds.size.height - 40, 300, 30)];

_tf.borderStyle = UITextBorderStyleRoundedRect;

[self.view addSubview:_tf];

/*

通知中心(单例)

通知中心是一对多的，即同一个广播可以被多个收音机接收

代理是一对一

作用：1.用来接收广播和发起广播

2.用通知的名字作为频道

*/

/*

参数一：响应的类

参数二：类中响应的方法

参数三：通知的名字(即频道)

参数四：接收类型 ［注意］nil代表任何类型

*/

//:UIKeyboardWillShowNotification接收键盘将要显示的通知

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyBoardWillShow:) name:UIKeyboardWillShowNotification object:nil];

//UIKeyboardWillHideNotification接收键盘将要隐藏的通知

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyBoardWillHide:) name:UIKeyboardWillHideNotification object:nil];

}

#pragma mark - UIKeyboardWillHideNotification

//键盘将要隐藏

-(void)keyBoardWillHide:(NSNotification *)noti

{

//noti.userInfo是一个字典，大家可以输出来看看字典里面包含了什么

//NSLog(@"%@",noti.userInfo);

　

//获得弹下去后的坐标[注意是弹下后的]

CGRect keyBoardEndFrame = [[noti.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];

//NSLog(@"--%@",NSStringFromCGRect(keyBoardEndFrame));

[UIView animateWithDuration:2 animations:^{

//改变文本框的位置，让它跟着键盘一起弹起来

CGRect tfRext = _tf.frame;

tfRext.origin.y = keyBoardEndFrame.origin.y-_tf.bounds.size.height-10;

_tf.frame = tfRext;

}];

}

#pragma mark - UIKeyBoard notification

//接收到的是通知，所以参数用NSNotification

//键盘将要显示

-(void)keyBoardWillShow:(NSNotification *)noti

{

CGRect keyBoardFrame = [[noti.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];

//可以通过以下方法输出CGRect

//NSStringFromCGRect将CGRect转化为字符串的方式获取Frame

//NSLog(@"%@",NSStringFromCGRect(keyBoardFrame));

//获取键盘的动画持续时间

//CGFloat keyBoardDuration = [noti.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];

[UIView animateWithDuration:2 animations:^{

CGRect tfRect = _tf.frame;

tfRect.origin.y = keyBoardFrame.origin.y - _tf.bounds.size.height -10;

_tf.frame = tfRect;

}];

}

#pragma mark - 当手指触碰屏幕任何一地方时被调用

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

{

//利用结束编辑来隐藏键盘

[self.view endEditing:YES];

}

@end