065监视文本输入框的状态

效果如下：

ViewController.h

1 #import <UIKit/UIKit.h>
2
3 @interface ViewController : UIViewController<UITextFieldDelegate>
4 @property (strong, nonatomic) UITextField *txtFMessage;
5
6 @end

ViewController.m

 1 #import "ViewController.h"
 2
 3 @interface ViewController ()
 4 - (void)layoutUI;
 5 @end
 6
 7 @implementation ViewController
 8
 9 - (void)viewDidLoad {
10     [super viewDidLoad];
11
12     [self layoutUI];
13 }
14
15 - (void)didReceiveMemoryWarning {
16     [super didReceiveMemoryWarning];
17     // Dispose of any resources that can be recreated.
18 }
19
20 - (void)layoutUI {
21     _txtFMessage = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 320, 80)];
22     _txtFMessage.center = self.view.center;
23     _txtFMessage.borderStyle = UITextBorderStyleRoundedRect;
24     _txtFMessage.text = @"通过NSLog确认delegate的设置";
25     _txtFMessage.textColor = [UIColor colorWithRed:0.342 green:1.000 blue:0.659 alpha:1.000];
26     _txtFMessage.textAlignment = NSTextAlignmentLeft;
27     _txtFMessage.contentHorizontalAlignment = UIControlContentVerticalAlignmentBottom;
28
29     //设置delegate
30     _txtFMessage.delegate = self;
31     _txtFMessage.clearButtonMode = UITextFieldViewModeAlways;
32     [self.view addSubview:_txtFMessage];
33
34     UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard:)];
35     [self.view addGestureRecognizer:gestureRecognizer];
36 }
37
38 /**
39  *  隐藏键盘
40  *
41  *  @param sender 事件触发者
42  */
43 - (IBAction)hideKeyboard:(id)sender {
44     NSLog(@"Tap Gesture Recognizer，去掉某些控件作为第一响应器");
45     [_txtFMessage resignFirstResponder];
46 }
47
48 #pragma mark - TextField
49 - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
50     NSLog(@"textFieldShouldBeginEditing: %@", textField.text);
51     return YES;
52 }
53
54 - (void)textFieldDidBeginEditing:(UITextField *)textField {
55     NSLog(@"textFieldDidBeginEditing: %@", textField.text);
56 }
57
58 - (BOOL)textFieldShouldEndEditing:(UITextField *)textField {
59     NSLog(@"textFieldShouldEndEditing: %@", textField.text);
60     return YES;
61 }
62
63 - (void)textFieldDidEndEditing:(UITextField *)textField {
64     NSLog(@"textFieldDidEndEditing: %@", textField.text);
65 }
66
67 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
68     NSLog(@"shouldChangeCharactersInRange: %@", string);
69     return YES;
70 }
71
72 - (BOOL)textFieldShouldClear:(UITextField *)textField {
73     NSLog(@"textFieldShouldClear: %@", textField.text);
74     return YES;
75 }
76
77 - (BOOL)textFieldShouldReturn:(UITextField *)textField {
78     NSLog(@"textFieldShouldReturn: %@", textField.text);
79     return YES;
80 }
81
82 @end

输出结果：

 1 2015-04-14 00:53:40.611 FirstBook065[1147:82365] Tap Gesture Recognizer，去掉某些控件作为第一响应器
 2 2015-04-14 00:53:45.359 FirstBook065[1147:82365] textFieldShouldBeginEditing: 通过NSLog确认delegate的设置
 3 2015-04-14 00:53:45.367 FirstBook065[1147:82365] textFieldDidBeginEditing: 通过NSLog确认delegate的设置
 4 2015-04-14 00:53:48.952 FirstBook065[1147:82365] textFieldShouldClear: 通过NSLog确认delegate的设置
 5 2015-04-14 00:53:51.164 FirstBook065[1147:82365] shouldChangeCharactersInRange: w
 6 2015-04-14 00:53:51.274 FirstBook065[1147:82365] shouldChangeCharactersInRange: e
 7 2015-04-14 00:53:59.771 FirstBook065[1147:82365] textFieldShouldReturn: 为什么我
 8 2015-04-14 00:54:04.832 FirstBook065[1147:82365] shouldChangeCharactersInRange: w
 9 2015-04-14 00:54:05.242 FirstBook065[1147:82365] shouldChangeCharactersInRange: w
10 2015-04-14 00:54:14.043 FirstBook065[1147:82365] textFieldShouldReturn: 为什么我ｗｗ
11 2015-04-14 00:54:15.889 FirstBook065[1147:82365] Tap Gesture Recognizer，去掉某些控件作为第一响应器
12 2015-04-14 00:54:15.889 FirstBook065[1147:82365] textFieldShouldEndEditing: 为什么我ｗｗ
13 2015-04-14 00:54:15.892 FirstBook065[1147:82365] textFieldDidEndEditing: 为什么我ｗｗ