UILabel宽高的计算

#import <UIKit/UIKit.h>

@interface UILabel (UILabelCategory)

- (CGSize)sizeWithMaxSize:(CGSize)maxSize;

@end

#import "UILabel+UILabelCategory.h"

@implementation UILabel (UILabelCategory)

- (CGSize)sizeWithMaxSize:(CGSize)maxSize
{
NSDictionary *dict = @{NSFontAttributeName: self.font};

//如果将来计算的文本小于指定的范围，那么返回的就是实际大小
//如果将来计算的文本超出了指定范围，那么返回的就是指定范围
CGSize size = [self.text boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:dict context:nil].size;

return size;
}