UILabel里字体带下划线2

#import <Foundation/Foundation.h>
@interface UnderlineUILabel : UILabel 
{

}

@end

#import "UnderlineUILabel.h"
#import<QuartzCore/QuartzCore.h>

@implementation UnderlineUILabel

-(id)initWithFrame:(CGRect)frame
{
if(self = [super initWithFrame:frame])
{
}
return self;
}
-(void)drawRect:(CGRect)rect 
{
[super drawRect:rect];
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGSize fontSize =[self.text sizeWithFont:self.font 
       forWidth:self.bounds.size.width
       lineBreakMode:UILineBreakModeTailTruncation];


       
// Get the fonts color. 
const float * colors = CGColorGetComponents([UIColor blueColor].CGColor);
// Sets the color to draw the line
CGContextSetRGBStrokeColor(ctx, colors[0], colors[1], colors[2], 1.0f); // Format : RGBA

// Line Width : make thinner or bigger if you want
CGContextSetLineWidth(ctx, 1.0f);

// Calculate the starting point (left) and target (right)
CGPoint l = CGPointMake(self.frame.size.width/2.0 - fontSize.width/2.0, 
          self.frame.size.height/2.0 +fontSize.height/2.0);
CGPoint r = CGPointMake(self.frame.size.width/2.0 + fontSize.width/2.0, 
         self.frame.size.height/2.0 + fontSize.height/2.0);


// Add Move Command to point the draw cursor to the starting point
CGContextMoveToPoint(ctx, l.x, l.y);

// Add Command to draw a Line
CGContextAddLineToPoint(ctx, r.x, r.y);


// Actually draw the line.
CGContextStrokePath(ctx);

// should be nothing, but who knows...
[super drawRect:rect];   
}

@end