在iphone中的文字下划线 [英] Text Underline in iphone

问题描述

如何在目标c iphone中加下划线？
是否有任何UILabel下划线文本的方法？

How to underline text in objective c iphone?? Is there any method for underline text of UILabel??

推荐答案

子类 UILabel 并覆盖 drawRect 方法如下。下划线将相同的文字颜色和文字对齐作为标签：

Subclass UILabel and override drawRect method as below. Underline will have the same text color and text alignment as the label:

- (void)drawRect:(CGRect)rect
{
    if([[self.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] length])
    {
        CGContextRef ctx = UIGraphicsGetCurrentContext();
        const CGFloat* colors = CGColorGetComponents(self.textColor.CGColor);
        CGContextSetRGBStrokeColor(ctx, colors[0], colors[1], colors[2], 1.0); // RGBA
        CGContextSetLineWidth(ctx, 1.0f);
        CGSize tmpSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(200, 9999)];

        // check text alignment
        if(self.textAlignment == UITextAlignmentLeft) {
            CGContextMoveToPoint(ctx, 0, self.bounds.size.height - 1);
            CGContextAddLineToPoint(ctx, tmpSize.width, self.bounds.size.height - 1);
        }else if(self.textAlignment == UITextAlignmentCenter) {
            CGFloat startPoint = (self.frame.size.width - tmpSize.width) / 2;
            CGContextMoveToPoint(ctx, startPoint, self.bounds.size.height - 1);
            CGContextAddLineToPoint(ctx, tmpSize.width + startPoint, self.bounds.size.height - 1);
        }else if (self.textAlignment == UITextAlignmentRight) {
            CGFloat startPoint = (self.frame.size.width - tmpSize.width);
            CGContextMoveToPoint(ctx, startPoint, self.bounds.size.height - 1);
            CGContextAddLineToPoint(ctx, self.frame.size.width, self.bounds.size.height - 1);
        }

        CGContextStrokePath(ctx);
    }
    [super drawRect:rect];
}

这篇关于在iphone中的文字下划线的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！