制作圆形表格的UIImage

Question

我一直试图将UIImage掩盖成一个圆圈.我现在正在使用其他答案中流行的代码,但是虽然我得到一个圆形,但它的边缘非常锯齿状而且不平滑.有人可以帮忙吗？我能得到一个完美,流畅的圆圈吗？

我用来创建掩码的代码是:

  (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage {

    CGImageRef imageNoAlpha = image.CGImage;

    CGColorSpaceRef cs = CGColorSpaceCreateDeviceRGB();

    CGFloat width = CGImageGetWidth(imageNoAlpha);
    CGFloat height = CGImageGetWidth(imageNoAlpha);

    CGContextRef ctxWithAlpha = CGBitmapContextCreate(nil, width, height, 8, 4*width, cs, kCGImageAlphaPremultipliedFirst);

    CGContextDrawImage(ctxWithAlpha, CGRectMake(0, 0, width, height), imageNoAlpha);

    CGImageRef imageWithAlpha = CGBitmapContextCreateImage(ctxWithAlpha);

    CGImageRef maskRef = maskImage.CGImage; 

    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
                                        CGImageGetHeight(maskRef),
                                        CGImageGetBitsPerComponent(maskRef),
                                        CGImageGetBitsPerPixel(maskRef),
                                        CGImageGetBytesPerRow(maskRef),
                                        CGImageGetDataProvider(maskRef), NULL, false);

    CGImageRef masked = CGImageCreateWithMask(imageWithAlpha, mask);

    UIImage* retImage= [UIImage imageWithCGImage:masked];
    UIImage* retImageFixed = [retImage transparentBorderImage:1];

    CGImageRelease(mask);
    CGImageRelease(masked);
    CGImageRelease(imageWithAlpha);
    CGContextRelease(ctxWithAlpha);
    CGColorSpaceRelease(cs);

    return retImageFixed;

提前致谢...

Answer 1

试试这段代码

yourImageView.layer.cornerRadius = yourImageView.frame.size.height /2;
yourImageView.layer.masksToBounds = YES;
yourImageView.layer.borderWidth = 0;

这个显示图像像ios 7圈图像谢谢

Answer 2

这可能对您有所帮助,将角半径作为参考视图的一半传递到要显示图像的位置,或者您可以设置自定义矩形,

例如.在我的情况下,我想在"imageView"上显示图像,因此在这种情况下,角半径将是imageView.frame.size.width/2

- (void)displayImage
{
    imageView.image = [self getRoundedRectImageFromImage:@"Test.png" onReferenceView:imageView withCornerRadius: imageView.frame.size.width/2];
}



- (UIImage *)getRoundedRectImageFromImage :(UIImage *)image onReferenceView :(UIImageView*)imageView withCornerRadius :(float)cornerRadius
{
    UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, NO, 1.0);
    [[UIBezierPath bezierPathWithRoundedRect:imageView.bounds
                                cornerRadius:cornerRadius] addClip];
    [image drawInRect:imageView.bounds];
    UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return finalImage;
}

Answer 3

抱歉丑陋的格式化.更好的版本的aToz的答案.

@interface UIImage (CircleMask)

+ (UIImage *)roundedRectImageFromImage :(UIImage *)image
                                  size :(CGSize)imageSize
                      withCornerRadius :(float)cornerRadius;

@end

@implementation UIImage(CircleMask)

+(UIImage*)roundedRectImageFromImage:(UIImage *)image
                                size:(CGSize)imageSize
                    withCornerRadius:(float)cornerRadius
{
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0);   //  <= notice 0.0 as third scale parameter. It is important cause default draw scale ? 1.0. Try 1.0 - it will draw an ugly image..
    CGRect bounds=(CGRect){CGPointZero,imageSize};
    [[UIBezierPath bezierPathWithRoundedRect:bounds
                                cornerRadius:cornerRadius] addClip];
    [image drawInRect:bounds];
    UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return finalImage;
}

@end

Swift中的同样的事情:

extension UIImage{

    class func roundedRectImageFromImage(image:UIImage,imageSize:CGSize,cornerRadius:CGFloat)->UIImage{
        UIGraphicsBeginImageContextWithOptions(imageSize,false,0.0)
        let bounds=CGRect(origin: CGPointZero, size: imageSize)
        UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).addClip()
        image.drawInRect(bounds)
        let finalImage=UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return finalImage
    }

}

Answer 4

一个更好的版本的aToz和fnc12的答案(在Swift中):

extension UIImage
{
    func roundImage() -> UIImage
    {
        let newImage = self.copy() as! UIImage
        let cornerRadius = self.size.height/2
        UIGraphicsBeginImageContextWithOptions(self.size, false, 1.0)
        let bounds = CGRect(origin: CGPointZero, size: self.size)
        UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).addClip()
        newImage.drawInRect(bounds)
        let finalImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return finalImage
    }
}

用法:

self.userImageView.image = image.roundedImage()