服务器之家

服务器之家 > 正文

IOS NSNotification 键盘遮挡问题的解决办法

时间:2021-03-31 16:13     来源/作者:最后的轻语

IOS NSNotification 键盘遮挡问题的解决办法

从键盘通知中获得键盘尺寸

键盘尺寸存在于NSNotification中。

1;在AddDrinkViewController中添加keyboardDidShow和keyboardDidHide方法

2;在viewWillAppear中注册UIKeyboardDidshowNotification与UIKeyboardDidHideNotification。

3;在viewWillDisappear中取消对所有事件的订阅注册

4;在AddDrinkViewController中添加一个Bool成员,跟踪键盘是否可见的状态。

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
//
// ViewController.h
// scrol
//
// Created by gao wuhang on 12-12-5.
// Copyright (c) 2012年 gao wuhang. All rights reserved.
//
 
#import
 
@interface ViewController : UIViewController{
  BOOL keyboardVisible;
  UIScrollView *scrollView;
}
 
- (void)keyboardDidShow: (NSNotification*) notif;
- (void)keyboardDidHide: (NSNotification*) notif;
 
@property (nonatomic, retain) UIScrollView *scrollView;
@end
 
 
//
// ViewController.m
// scrol
//
// Created by gao wuhang on 12-12-5.
// Copyright (c) 2012年 gao wuhang. All rights reserved.
//
 
#import "ViewController.h"
 
@interface ViewController ()
 
@end
 
@implementation ViewController
 
@synthesize scrollView;
 
- (void)viewWillAppear:(BOOL)animated{
  [super viewWillAppear:animated];
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidHide:) name:UIKeyboardDidHideNotification object:nil];
}
 
- (void)viewWillDisappear:(BOOL)animated{
  [[NSNotificationCenter defaultCenter] removeObserver:self];
}
 
- (void) keyboardDidShow:(NSNotification *)notif {
NSLog(@"%@", @"Received UIKeyboardDidShowNotification");
 
if (keyboardVisible) {
NSLog(@"%@", @"Keyboard is already visible. Ignoring notifications.");
return;
}
 
// The keyboard wasn't visible before
NSLog(@"Resizing smaller for keyboard");
 
// Get the origin of the keyboard when it finishes animating
NSDictionary *info = [notif userInfo];
NSValue *aValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
 
// Get the top of the keyboard in view's coordinate system.
// We need to set the bottom of the scrollview to line up with it
CGRect keyboardRect = [aValue CGRectValue];
  keyboardRect = [self.view convertRect:keyboardRect fromView:nil];
CGFloat keyboardTop = keyboardRect.origin.y;
  
// Resize the scroll view to make room for the keyboard
  CGRect viewFrame = self.view.bounds;
viewFrame.size.height = keyboardTop - self.view.bounds.origin.y;
 
self.scrollView.frame = viewFrame;
keyboardVisible = YES;
}
 
- (void) keyboardDidHide:(NSNotification *)notif {
NSLog(@"%@", @"Received UIKeyboardDidHideNotification");
 
if (!keyboardVisible) {
NSLog(@"%@", @"Keyboard already hidden. Ignoring notification.");
return;
}
 
// The keyboard was visible
NSLog(@"%@", @"Resizing bigger with no keyboard");
  
// Resize the scroll view back to the full size of our view
self.scrollView.frame = self.view.bounds;
keyboardVisible = NO;
}
 
- (void)viewDidLoad
{
  scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 460)];
//  scroll.contentSize = CGSizeMake(1000, 1000);
  [self.view addSubview:scrollView];
//  UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
//  [button setBackgroundColor:[UIColor blackColor]];
//  [scroll addSubview:button];
  UITextView *textView = [[UITextView alloc]initWithFrame:CGRectMake(100, 300, 100, 100)];
  textView.text = @"222";
  textView.font = [UIFont systemFontOfSize:20];
  [scrollView addSubview:textView];
  [super viewDidLoad];
  [textView release];
 
  self.scrollView.contentSize = self.view.frame.size;
// Do any additional setup after loading the view, typically from a nib.
}
 
- (void)dealloc
{
  [scrollView release];
  [super dealloc];
}
 
- (void)didReceiveMemoryWarning
{
  [super didReceiveMemoryWarning];
  // Dispose of any resources that can be recreated.
}
 
@end

如有疑问请留言或者到本站社区交流讨论,感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!

原文链接:http://blog.sina.com.cn/s/blog_68edaff101019y2c.html

相关文章

热门资讯

2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全
2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全 2019-12-26
yue是什么意思 网络流行语yue了是什么梗
yue是什么意思 网络流行语yue了是什么梗 2020-10-11
背刺什么意思 网络词语背刺是什么梗
背刺什么意思 网络词语背刺是什么梗 2020-05-22
Intellij idea2020永久破解,亲测可用!!!
Intellij idea2020永久破解,亲测可用!!! 2020-07-29
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总 2020-11-13
返回顶部