iPhone获取字符串高度和宽度 …

通常我们使用UILabel只是显示较短的字符串，下面是一种获取字符串的换行高度，显示

 

  代码如下所示:

[cpp] view plain copy print ?

1. NSString* str = @"test testImplement viewDidLoad to do additional setup after loading the view, typically from a nib";  
2.   
3. //CGSize labelSize =  [str sizeWithFont:[UIFont systemFontOfSize:14]];      
4.   
5. //可以精确计算字符串的换行，高宽等   
6. CGSize labelSize = [str sizeWithFont:[UIFont boldSystemFontOfSize:17.0f]  
7.                         constrainedToSize:CGSizeMake(280, 100)   
8.                         lineBreakMode:UILineBreakModeCharacterWrap];  
9.   
10. UILabel* label = [[UILabel alloc] init];  
11. label.frame = CGRectMake(50, 20, labelSize.width, labelSize.height);  
12. label.backgroundColor = [UIColor whiteColor];  
13. label.text = str;  
14. label.font = [UIFont systemFontOfSize:17.0f];  
15. label.numberOfLines = 0;  
16. label.lineBreakMode = UILineBreakModeCharacterWrap;  
17.   
18. [self.view addSubview:label];  
19. [label release];  

        NSString* str = @"test testImplement viewDidLoad to do additional setup after loading the view, typically from a nib";

        //CGSize labelSize =  [str sizeWithFont:[UIFont systemFontOfSize:14]];   
        
        //可以精确计算字符串的换行，高宽等
        CGSize labelSize = [str sizeWithFont:[UIFont boldSystemFontOfSize:17.0f]
                                                constrainedToSize:CGSizeMake(280, 100) 
                                                    lineBreakMode:UILineBreakModeCharacterWrap];
        
        UILabel* label = [[UILabel alloc] init];
        label.frame = CGRectMake(50, 20, labelSize.width, labelSize.height);
        label.backgroundColor = [UIColor whiteColor];
        label.text = str;
        label.font = [UIFont systemFontOfSize:17.0f];
        label.numberOfLines = 0;
        label.lineBreakMode = UILineBreakModeCharacterWrap;
        
        [self.view addSubview:label];
        [label release];