使用圆角和边框制作UIImage

Question

我有一个UIImage,我需要使用白色边框.我不需要UIImageView这个.

你怎么做到这一点？

Answer 1

您可以使用QuartzCore函数创建图像上下文,绘制剪切的图像,然后描绘路径:

- (UIImage *)imageWithBorderAndRoundCornersWithImage:(UIImage *)image lineWidth:(CGFloat)lineWidth cornerRadius:(CGFloat)cornerRadius {
    UIGraphicsBeginImageContextWithOptions(image.size, false, image.scale);
    CGRect rect = CGRectZero;
    rect.size = image.size;
    CGRect pathRect = CGRectInset(rect, lineWidth / 2.0, lineWidth / 2.0);

    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSaveGState(context);

    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:pathRect cornerRadius:cornerRadius];

    CGContextBeginPath(context);
    CGContextAddPath(context, path.CGPath);
    CGContextClosePath(context);
    CGContextClip(context);

    [image drawAtPoint:CGPointZero];

    CGContextRestoreGState(context);

    [[UIColor whiteColor] setStroke];
    path.lineWidth = lineWidth;
    [path stroke];

    UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return finalImage;
}

这需要:

并使: