运行阶段
当我们输入的时候，触发顺序为
- textFieldShouldBeginEditing
- textFieldDidBeginEditing
当我们按回车的时候
- textFieldShouldReturn
- textFieldShouldEndEditing
- textFieldDidEndEditing
然后我们在textFieldShouldReturn方法中写入代码
[self.myTextField endEditing];
就可以将键盘收起
关闭键盘的两种方式
endEditing vs resignFirstResponder
self.view.endEditing(true) is less efficient because it will cycle through the entire view hierarchy and makes sure anything that can be a firstRepsonder has resigned it.
endEditing会遍历整个视图，确保所有的能够重置为firstResponder的组件进行重置，效率会略低。
If you know which item is currently the responder, it is more efficient and better practice to call resignFirstResponder on it directly.
如果你知道当前的响应者是哪个元素，那么直接重置该元素会是非常高效的。
代码段
#import "ModalViewController.h"@interface ModalViewController ()- (IBAction)cancelButton:(id)sender;- (IBAction)save:(id)sender;@property (weak, nonatomic) IBOutlet UITextField *myTextField;@end@implementation ModalViewController- (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. self.myTextField.delegate = self; }- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField { NSLog(@"%@",[[NSString alloc] initWithCString:__FUNCTION__ encoding:NSASCIIStringEncoding]); return TRUE;}- (void)textFieldDidBeginEditing:(UITextField *)textField { NSLog(@"%@", [[NSString alloc] initWithCString:__FUNCTION__ encoding:NSASCIIStringEncoding]);}- (BOOL)textFieldShouldEndEditing:(UITextField *)textField { NSLog(@"%@", [[NSString alloc] initWithCString:__FUNCTION__ encoding:NSASCIIStringEncoding]); return TRUE;}- (void)textFieldDidEndEditing:(UITextField *)textField { NSLog(@"%@", [[NSString alloc] initWithCString:__FUNCTION__ encoding:NSASCIIStringEncoding]);}- (BOOL)textFieldShouldReturn:(UITextField *)textField { NSLog(@"%@",[[NSString alloc] initWithCString:__FUNCTION__ encoding:NSASCIIStringEncoding]); [self.myTextField endEditing:TRUE]; return TRUE;}- (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated.}/*#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { // Get the new view controller using [segue destinationViewController]. // Pass the selected object to the new view controller.}*/- (IBAction)cancelButton:(id)sender { [self dismissViewControllerAnimated:TRUE completion:^{ NSLog(@"close2"); }];}- (IBAction)save:(id)sender { // NSURL *url = [NSURL URLWithString:@"https://baidu.com"]; // [[UIApplication sharedApplication] openURL:url]; // [[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://10086"]]; [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms://10086"] options:@{} completionHandler:^(BOOL success) { NSLog(@"sms success:%@",success ? @"YES": @"NO"); }]; }@end