UILabel Text 加下划线

.h文件
#import <Foundation/Foundation.h>
 
@interface CustomLabel : UILabel
{
    BOOL _isEnabled;
}
 
@property (nonatomic ) BOOL isEnabled;
 
@end
 
.m文件
#import "CustomLabel.h"
 
@implementation CustomLabel
 
@synthesize isEnabled = _isEnabled;
 
- (void)drawTextInRect:(CGRect)rect{
    [super drawTextInRect:rect];
 
    CGSize textSize = [[self text] sizeWithFont:[self font]];
    CGFloat strikeWidth = textSize.width;
    CGRect lineRect;
 
    if ([self textAlignment] == NSTextAlignmentRight) {
        lineRect = CGRectMake(rect.size.width - strikeWidth, rect.size.height/, strikeWidth, );
    } else if ([self textAlignment] == NSTextAlignmentCenter) {
        lineRect = CGRectMake(rect.size.width/ - strikeWidth/, rect.size.height/, strikeWidth, );
    } else {
        lineRect = CGRectMake(, rect.size.height/, strikeWidth, );
    }
 
    if (_isEnabled) {
        CGContextRef context = UIGraphicsGetCurrentContext();
        CGContextFillRect(context, lineRect);
    }
}
 
// 调用
 
CustomLabel *_label;
 _label = [[CustomLabel alloc]initWithFrame:CGRectMake(, , , )];
 _label.text = @"这是一个多么美好的世界啊";
 _label.backgroundColor = [UIColor clearColor];
 _label.isEnabled = YES;
 [_label sizeToFit];
  _label.textColor = [UIColor redColor];
 [self.view addSubview:_label];