[转载]关于UITextField的键盘遮挡问题

1 前言
　　平时做App的时候总会遇到，UITextField的键盘会遮挡住下面的内容，由于IOS没有自己的机制，所以需要自己写方法来控制，今天我们就介绍一种简单的方法，来应对键盘遮挡问题。

2 代码实例

ZYViewController.h

 1 #import <UIKit/UIKit.h> 
 2  
 3 @interface ZYViewController : UIViewController<UITextFieldDelegate> 
 4  
 5 @property(nonatomic,strong) UITextField *myTextField; 
 6  
 7 @end 
 8 
 9 #import <UIKit/UIKit.h>
10 
11 @interface ZYViewController : UIViewController<UITextFieldDelegate>
12 
13 @property(nonatomic,strong) UITextField *myTextField;
14 
15 @end

ZYViewController.m

 1 @synthesize myTextField; 
 2  
 3 - (void)viewDidLoad 
 4 { 
 5     [super viewDidLoad]; 
 6     //Do any additional setup after loading the view, typically from a nib. 
 7     //self.view.backgroundColor = [UIColor underPageBackgroundColor]; 
 8     myTextField = [[UITextField alloc] init];//初始化UITextField 
 9     myTextField.frame = CGRectMake(35, 230, 250, 35); 
10     myTextField.delegate = self;//设置代理 
11     myTextField.borderStyle = UITextBorderStyleRoundedRect; 
12     myTextField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;//垂直居中 
13     myTextField.placeholder = @"Please entry your content!";//内容为空时默认文字 
14     myTextField.returnKeyType = UIReturnKeyDone;//设置放回按钮的样式 
15     myTextField.keyboardType = UIKeyboardTypeNumbersAndPunctuation;//设置键盘样式为数字 
16     [self.view addSubview:myTextField]; 
17      
18      
19     //注册键盘出现与隐藏时候的通知 
20     [[NSNotificationCenter defaultCenter] addObserver:self 
21                                              selector:@selector(keyboadWillShow:) 
22                                              name:UIKeyboardWillShowNotification 
23                                              object:nil]; 
24     [[NSNotificationCenter defaultCenter] addObserver:self 
25                                              selector:@selector(keyboardWillHide:) 
26                                           name:UIKeyboardWillHideNotification 
27                                           object:nil]; 
28     //添加手势，点击屏幕其他区域关闭键盘的操作 
29     UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard)]; 
30     gesture.numberOfTapsRequired = 1;//手势敲击的次数 
31     [self.view addGestureRecognizer:gesture]; 
32 } 
33  
34 //键盘出现时候调用的事件 
35 -(void) keyboadWillShow:(NSNotification *)note{ 
36     NSDictionary *info = [note userInfo]; 
37     CGSize keyboardSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;//键盘的frame 
38     CGFloat offY = (460-keyboardSize.height)-myTextField.frame.size.height;//屏幕总高度-键盘高度-UITextField高度 
39     [UIView beginAnimations:nil context:NULL];//此处添加动画，使之变化平滑一点 
40     [UIView setAnimationDuration:0.3];//设置动画时间 秒为单位 
41     myTextField.frame = CGRectMake(35, offY, 250, 35);//UITextField位置的y坐标移动到offY 
42     [UIView commitAnimations];//开始动画效果 
43      
44 } 
45 //键盘消失时候调用的事件 
46 -(void)keyboardWillHide:(NSNotification *)note{ 
47     [UIView beginAnimations:nil context:NULL];//此处添加动画，使之变化平滑一点 
48     [UIView setAnimationDuration:0.3]; 
49     myTextField.frame = CGRectMake(35, 230, 250, 35);//UITextField位置复原 
50  
51     [UIView commitAnimations]; 
52 } 
53 //隐藏键盘方法 
54 -(void)hideKeyboard{ 
55     [myTextField resignFirstResponder]; 
56 } 
57 #pragma mark - 
58 #pragma mark UITextFieldDelegate 
59 //开始编辑： 
60 - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField 
61 { 
62     return YES; 
63 } 
64  
65 //点击return按钮所做的动作： 
66 - (BOOL)textFieldShouldReturn:(UITextField *)textField 
67 { 
68     [textField resignFirstResponder];//取消第一响应 
69     return YES; 
70 } 
71  
72 //编辑完成： 
73 - (void)textFieldDidEndEditing:(UITextField *)textField 
74 { 
75      
76 } 
77  
78 -(void)viewDidDisappear:(BOOL)animated{ 
79     [super viewDidDisappear:animated]; 
80     [[NSNotificationCenter defaultCenter] removeObserver:self];//移除观察者 
81 }

运行结果：

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