iOS OC 为button添加下划线

最近做的一个项目里需要在button里的titleLable里添加下滑线，自己搞了半小时，重写了个button。

贴代码：

UnderlineButton.h

#import<UIKit/UIKit.h>

@interface UnderlineButton : UIButton

{

UIColor *lineColor;

}

-(void)setColor:(UIColor*)color;

@end

UnderlineButton.m

#import "UnderlineButton.h"

@implementation UnderlineButton

- (id)initWithFrame:(CGRect)frame

{

self = [super initWithFrame:frame];

if (self) {

}

return self;

}

-(void)setColor:(UIColor *)color{

lineColor = [color copy];

[self setNeedsDisplay];

}

- (void) drawRect:(CGRect)rect {

CGRect textRect = self.titleLabel.frame;

CGContextRef contextRef = UIGraphicsGetCurrentContext();

CGFloat descender = self.titleLabel.font.descender;

if([lineColor isKindOfClass:[UIColor class]]){

CGContextSetStrokeColorWithColor(contextRef, lineColor.CGColor);

}

CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y + textRect.size.height + descender+1);

CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + textRect.size.height + descender+1);

CGContextClosePath(contextRef);

CGContextDrawPath(contextRef, kCGPathStroke);

}

@end

直接复制粘贴即可用。