iOS UILabel 文字自动左上角对齐

iOS中默认的UILabel是垂直居中对齐的，如果UILabel设置的高度较大，当内容少的时候，会自动垂直居中。

创建一个  UILabel的category

代码如下：

 
#import 

@interface UILabel (LeftTopAlign)
- (void) textLeftTopAlign;
@end
 

 

 
 #import "UILabel+LeftTopAlign.h"

@implementation UILabel (LeftTopAlign)

- (void) textLeftTopAlign
{
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
    paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
    
    NSDictionary *attributes = @{NSFontAttributeName:[UIFont systemFontOfSize:12.f], NSParagraphStyleAttributeName:paragraphStyle.copy};
    
    CGSize labelSize = [self.text boundingRectWithSize:CGSizeMake(207, 999) options:NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil].size;
    
    CGRect dateFrame =CGRectMake(2, 140, CGRectGetWidth(self.frame)-5, labelSize.height);
    self.frame = dateFrame;
}
@end
  

在需要的时候，只需要直接调用即可。

 
#import "UILabel+LeftTopAlign.h"
-(void)someMethod:(UILabel*)label
{ 
  [label textLeftTopAlign];
}