1 #import "ViewController.h"
2
3 @implementation ViewController
4
5 - (void)viewDidLoad {
6 [super viewDidLoad];
7
8 //根据固定的宽度计算 计算label的高度
9 [self sizeToLabelHeight];
10
11 //根据固定的高度 计算label的宽度
12 [self sizeToLabelWidth];
13
14 }
15
16 /**
17 * 自动计算label的宽度 前提高度固定
18 *
19 */
20 - (void)sizeToLabelWidth
21 {
22 UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
23 label.textColor = [UIColor whiteColor];
24 label.font = [UIFont systemFontOfSize:13];
25 label.numberOfLines = 0; //这个属性 一定要设置为0 0表示自动换行 默认是1 不换行
26 label.backgroundColor = [UIColor blackColor];
27 label.textAlignment = NSTextAlignmentLeft;
28 NSString *str = @"fsdfsfnksdfjsdkhfjksdhfjdolfsdfsfnksdfjsdkhfjksdhfjsdkhfjksdhfjdojdol";
29
30
31 //第一种方式
32 // CGSize size = [str sizeWithFont:label.font constrainedToSize: CGSizeMake(MAXFLOAT,label.frame.size.height) lineBreakMode:NSLineBreakByWordWrapping];
33
34 //第二种方式
35
36 NSMutableDictionary *attrs = [NSMutableDictionary dictionary];
37 attrs[NSFontAttributeName] = [UIFont systemFontOfSize:13];
38
39 CGSize size = [str boundingRectWithSize:CGSizeMake( MAXFLOAT,label.frame.size.height) options:NSStringDrawingUsesLineFragmentOrigin attributes:attrs context:nil].size;
40
41 label.frame = CGRectMake(5, 0, size.width, 100);
42 label.text = str;
43
44 [self.view addSubview:label];
45 }
46
47
48 /**
49 * 自动计算label的高度 前提 ：宽度固定
50 */
51 - (void)sizeToLabelHeight
52 {
53
54 UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
55 label.textColor = [UIColor whiteColor];
56 label.font = [UIFont systemFontOfSize:13];
57 label.numberOfLines = 0;//这个属性 一定要设置为0 0表示自动换行 默认是1 不换行
58 label.backgroundColor = [UIColor blackColor];
59 label.textAlignment = NSTextAlignmentLeft;
60
61 NSString *str = @"fsdfsfnksdfjsdkhfjksdhfjdolfsdfsfnksdfjsdkhfjksdhfjsdkhfjksdhfjdojdol";
62
63 //第一种方式
64 // CGSize size = [str sizeWithFont:label.font constrainedToSize: CGSizeMake(label.frame.size.width, MAXFLOAT) lineBreakMode:NSLineBreakByWordWrapping];
65
66 //第二种方式
67 NSMutableDictionary *attrs = [NSMutableDictionary dictionary];
68 attrs[NSFontAttributeName] = [UIFont systemFontOfSize:13];
69
70 CGSize size = [str boundingRectWithSize:CGSizeMake(label.frame.size.width, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:attrs context:nil].size;
71
72 label.frame = CGRectMake(100, 100, 100, size.height);
73 label.text = str;
74
75 [self.view addSubview:label];
76 }
77
78
79 @end
