iOS开发Label文字显示位置（上、中、下）

毛蛋發表於 2020-6-1 09:49:00

iOS开发Label文字显示位置（上、中、下）

<img src="https://img2020.cnblogs.com/blog/2043045/202006/2043045-20200601094454811-706402565.png">
在系统自带的UILabel中是没有吸顶及吸底部的方法的（如果有请告诉我，我没找到），于是乎重写label
<div class="cnblogs_code">
<pre> 1 //
 2 //gzhVerticalAlignmentLabel.h
 3 //VerticalAlignmentLabel
 4 //
 5 //Created by 郭志贺 on 2020/6/1.
 6 //Copyright © 2020 郭志贺. All rights reserved.
 7 //
 8
 9 #import <UIKit/UIKit.h>
10
11 NS_ASSUME_NONNULL_BEGIN
12
13 typedef enum VerticalAlignment {
14
15 VerticalAlignmentTop,
16
17 VerticalAlignmentMiddle,
18
19 VerticalAlignmentBottom,
20
21 } VerticalAlignment;
22
23 @interface gzhVerticalAlignmentLabel : UILabel{
24
25 @private VerticalAlignment verticalAlignment_;
26
27 }
28
29
30
31 @property (nonatomic, assign) VerticalAlignment verticalAlignment;
32
33 @end
34
35 NS_ASSUME_NONNULL_END</pre>
</div>
<div class="cnblogs_code">
<pre> 1 //
 2 //gzhVerticalAlignmentLabel.m
 3 //VerticalAlignmentLabel
 4 //
 5 //Created by 郭志贺 on 2020/6/1.
 6 //Copyright © 2020 郭志贺. All rights reserved.
 7 //
 8
 9 #import "gzhVerticalAlignmentLabel.h"
10
11 @implementation gzhVerticalAlignmentLabel
12
13 @synthesize verticalAlignment = verticalAlignment_;
14
15
16
17
18 - (void)setVerticalAlignment:(VerticalAlignment)verticalAlignment {
19
20 verticalAlignment_ = verticalAlignment;
21
22 ;
23
24 }
25
26
27
28 - (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
29
30 CGRect textRect = ;
31
32 switch (self.verticalAlignment) {
33
34 case VerticalAlignmentTop:
35
36 textRect.origin.y = bounds.origin.y;
37
38 break;
39
40 case VerticalAlignmentBottom:
41
42 textRect.origin.y = bounds.origin.y + bounds.size.height - textRect.size.height;
43
44 break;
45
46 case VerticalAlignmentMiddle:
47
48
49 default:
50
51 textRect.origin.y = bounds.origin.y + (bounds.size.height - textRect.size.height) / 2.0;
52
53 }
54
55 return textRect;
56
57 }
58
59
60
61 -(void)drawTextInRect:(CGRect)requestedRect {
62
63 CGRect actualRect = ;
64
65 ;
66
67 }
68
69 @end</pre>
</div>
使用方式
<div class="cnblogs_code">
<pre> 1 //
 2 //ViewController.m
 3 //VerticalAlignmentLabel
 4 //
 5 //Created by 郭志贺 on 2020/6/1.
 6 //Copyright © 2020 郭志贺. All rights reserved.
 7 //
 8
 9 #import "ViewController.h"
10 #import "gzhVerticalAlignmentLabel.h"
11
12 /** 屏幕高度 */
13 #define ScreenH .bounds.size.height
14 /** 屏幕宽度 */
15 #define ScreenW .bounds.size.width
16
17 @interface ViewController ()
18
19 @property(nonatomic,strong)gzhVerticalAlignmentLabel * topLabel;
20 @property(nonatomic,strong)gzhVerticalAlignmentLabel * centerLabel;
21 @property(nonatomic,strong)gzhVerticalAlignmentLabel * bottomLabel;
22
23 @end
24
25 @implementation ViewController
26
27 - (void)viewDidLoad {
28 ;
29 // Do any additional setup after loading the view.
30
31 _topLabel = [initWithFrame:CGRectMake((ScreenW-200)/2.0, 100, 200, 80)];
32 _topLabel.verticalAlignment = VerticalAlignmentTop;
33 _topLabel.backgroundColor = ;
34 _topLabel.font = ;
35 _topLabel.textAlignment = NSTextAlignmentCenter;
36 _topLabel.text = @"文字顶部显示";
37 ;
38
39 _centerLabel = [initWithFrame:CGRectMake((ScreenW-200)/2.0, CGRectGetMaxY(_topLabel.frame)+10, 200, 80)];
40 _centerLabel.verticalAlignment = VerticalAlignmentMiddle;
41 _centerLabel.backgroundColor = ;
42 _centerLabel.font = ;
43 _centerLabel.textAlignment = NSTextAlignmentCenter;
44 _centerLabel.text = @"文字中间显示";
45 ;
46
47
48 _bottomLabel = [initWithFrame:CGRectMake((ScreenW-200)/2.0, CGRectGetMaxY(_centerLabel.frame)+10, 200, 80)];
49 _bottomLabel.verticalAlignment = VerticalAlignmentBottom;
50 _bottomLabel.backgroundColor = ;
51 _bottomLabel.font = ;
52 _bottomLabel.textAlignment = NSTextAlignmentCenter;
53 _bottomLabel.text = @"文字底部显示";
54 ;
55 }
56
57
58 @end</pre>
</div>
 <img src="https://img2020.cnblogs.com/blog/2043045/202006/2043045-20200601105244464-2104702882.jpg"> 
来源：https://www.cnblogs.com/guozhihe/p/13023566.html

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iOS开发Label文字显示位置（上、中、下）