iOS image-图片设置圆角

iOS image-图片设置圆角实质上是重绘图片 

此代码用于实现UIImage圆角，而不是UIImageView圆角，UIImageView圆角可以直接通过如下实现 imageView.layer.cornerRadius = radius; imageView.layer.masksToBounds = YES;

//方法1 - (UIImage *)imageWithRoundedCornersSize:( float )cornerRadius usingImage:(UIImage *)original { CGRect frame = CGRectMake(0, 0, original.size.width, original.size.height); // Begin a new image that will be the new image with the rounded corners // (here with the size of an UIImageView) UIGraphicsBeginImageContextWithOptions(original.size, NO, 1.0); // Add a clip before drawing anything, in the shape of an rounded rect [[UIBezierPath bezierPathWithRoundedRect:frame cornerRadius:cornerRadius] addClip]; // Draw your image [original drawInRect:frame]; // Retrieve and return the new image UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; } //方法2 -(UIImage *)makeRoundedImage:(UIImage *) image radius: ( float ) radius; { CALayer *imageLayer = [CALayer layer]; imageLayer.frame = CGRectMake(0, 0, image.size.width, image.size.height); imageLayer.contents = (id) image.CGImage; imageLayer.masksToBounds = YES; imageLayer.cornerRadius = radius; UIGraphicsBeginImageContext(image.size); [imageLayer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return roundedImage; }