iOS之矩形图片切割成圆形图片

在 iOS 开发中，有些情况往往需要对图片进行切割。比如说音频播放器中的专辑图片，需要显示成圆形转动效果，而图片资源往往都是矩形的，此时就很有必要把矩形图片切割成圆形。

/*!
	@function       convertToCircleWithImage:onWidth:onColor
 
	@discussion     Convert rectangle to circle with image .
 
	@param			rectangleImage
                        source image
    @param          width
                        Border with after convert.
	@param			color
                        Color with after convert.
 */
+(UIImage *)convertToCircleWithImage:(UIImage *)rectangleImage
                             onWidth:(CGFloat)width
                             onColor:(UIColor *)color
{
    
    CGFloat imageWidth = rectangleImage.size.width + 2 * width;    
    CGFloat imageHeight = rectangleImage.size.height + 2 * width;
    
    UIGraphicsBeginImageContextWithOptions(CGSizeMake(imageWidth, imageHeight), NO, 0.0);
    
    UIGraphicsGetCurrentContext();
    
    CGFloat radius = (rectangleImage.size.width < rectangleImage.size.height
                      ? rectangleImage.size.width : rectangleImage.size.height) * 0.5;
    
    UIBezierPath *bezierPath = [UIBezierPath
                                bezierPathWithArcCenter:CGPointMake(imageWidth * 0.5, imageHeight * 0.5)
                                radius:radius startAngle:0 endAngle:M_PI * 2 clockwise:YES];
    
    bezierPath.lineWidth = width;
    [color setStroke];
    [bezierPath stroke];
    [bezierPath addClip];
    
    [rectangleImage drawInRect:CGRectMake(width, width, rectangleImage.size.width, rectangleImage.size.height)];
    
    UIImage *circleImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return circleImage;
}

声明：此博文源自 http://blog.csdn.net/shenyuanluo/article/details/49122927

如需转载，请说明博文出处。谢谢！