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项目中偶尔会有带边框图片的需求,或是头像亦或是logo.在原型图片外围加一自定义颜色的边框,思路是根据上下文绘制,写了Demo和解释.
带边框的图片Demo:
-(void)borderImage{
//1.加载图片
UIImage *image = [UIImage imageNamed:@"baby"];
//2.边框宽度
CGFloat borderW = 10;
//3.开启图片上下文
CGSize size = CGSizeMake(image.size.width+2*borderW, image.size.height+2*borderW);
UIGraphicsBeginImageContextWithOptions(size, NO, 0);
//4.先描述一个大圆作为填充
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, size.width, size.height)];
[[UIColor redColor] set];
[path fill];
//5.在添加一个小圆设为剪裁区域
path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(borderW, borderW, image.size.width, image.size.height)];
[path addClip];
//6.把图片绘制上下文
[image drawInRect:CGRectMake(borderW, borderW, image.size.width, image.size.height)];
//7.生成图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
//8.关闭上下文
UIGraphicsEndImageContext();
self.imageV.image = newImage;
}
方便调用的UIIamge的分类:
/**
* 带边框的图片
*
* @param imageName 图片名
* @param imageWidth 图片宽度
* @param imageHeight 图片高度
* @param borderWidth 边框宽度
* @param borderColor 边框颜色
*
* @return 带边框的图片
*/
+(UIImage *)imageWithImageName:(NSString *)imageName imageWidth:(CGFloat)imageWidth imageHeight:(CGFloat)imageHeight borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)borderColor{
UIImage *image = [UIImage imageNamed:imageName];
CGSize size = CGSizeMake(imageWidth + 2 * borderWidth, imageHeight + 2 * borderWidth);
UIGraphicsBeginImageContextWithOptions(size, NO, 0);
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, size.width, size.height)];
[borderColor set];
[path fill];
path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(borderWidth, borderWidth, imageWidth, imageHeight)];
[path addClip];
[image drawInRect:CGRectMake(borderWidth, borderWidth, imageWidth, imageHeight)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
完整项目Demo链接:
https://github.com/qxuewei/XWBorderImage
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原文地址:http://blog.csdn.net/qxuewei/article/details/52160259