Iphone 将图像制作成圆形

我一直在试图把一个UIImage遮罩成一个圆圈。 我现在使用的代码在其他答案中很流行，但尽管我得到了一个圆，但它的边缘非常参差不齐且不平滑。 有人能帮忙吗？我能得到一个完美光滑的圆吗

我用来创建遮罩的代码是：

  (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;

---

提前感谢…

这可能会帮助您，将拐角半径作为要显示图像的参考视图的一半，或者您可以设置自定义矩形

例如，在我的例子中，我想在的“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;
}

试试这个代码

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

此显示的图像与ios 7 circle图像类似，非常感谢

对不起，格式太难看了。 阿托兹答案的更好版本

@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

---

如果您使用的是

UIImageView

，并且希望在保持圆角的同时设置图像大小的动画，则可以按如下方式应用变换：

目标-C

迅捷的

---

注意：这也将保留任何自动布局

约束

aToz和fnc12答案的更好版本（Swift）：

用法：

self.userImageView.image = image.roundedImage()

---

我使用UIBezierPath解决问题

UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:yourImageView.bounds];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.path = path.CGPath;
yourImageView.layer.mask = maskLayer;

---

从UIImageView获得帮助怎么样

+ (UIImage *)circularImage:(UIImage *)image withDiameter:(NSUInteger)diameter
{
    CGRect frame = CGRectMake(0.0f, 0.0f, diameter, diameter);
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:frame];
    imageView.contentMode = UIViewContentModeScaleAspectFill;
    imageView.clipsToBounds = YES;
    imageView.image = image;
    CALayer *layer = imageView.layer;


    layer.masksToBounds = YES;

    layer.cornerRadius =MAX( imageView.frame.size.height,imageView.frame.size.width)/2;

    UIGraphicsBeginImageContextWithOptions(imageView.bounds.size,NO, [UIScreen mainScreen].scale);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [layer renderInContext:context];


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

    return roundedImage;
}

---

如果您使用的是Swift，则可以导入“AlamofireImage”，并使用其功能之一。对于圆形图像：

let roundImage = UIImage(named: "myImage")!.af_imageRoundedIntoCircle()

---

试试这个

UIImageView *circleImageview=[[UIImageView alloc]init];
circleImageview.frame=CGRectMake(0,10, 80, 80)]; 
circleImageview.layer.cornerRadius=circleimagview.frame.size.height/2;
 circleImageview.userInteractionEnabled=YES;
 [self.view addSubview:circleImageview];

---

注意：确保高度和宽度与该视图相同。

感觉我应该把帽子扔进戒指里。高效、紧凑的Swift 5解决方案：

extension UIImage {

    var rounded: UIImage? {
        UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.main.scale)
        defer { UIGraphicsEndImageContext() }
        let bounds = CGRect(origin: .zero, size: size)
        UIBezierPath(roundedRect: bounds, cornerRadius: size.height/2.0).addClip()
        draw(in: bounds)
        return UIGraphicsGetImageFromCurrentImageContext()
    }

}

---

可能是。这两个链接可能有助于你寻找什么。1.2.谢谢我见过很多人说，你可以只使用角半径属性，但那是错误的。虽然它确实会使角变圆，但它不会使所有图像看起来像一个圆。仅供参考，此解决方案会使表格视图中的滚动变慢@aToz的解决方案工作得很好。它在tableView滚动中工作得很好，我看不出有任何问题，我的tableView包含246行，每行从服务器加载图像，并且仍然工作perfectly@aLFaRSi您正在运行什么类型的设备？性能差的代码并不总是在一开始就表现出来。这两种方法可能都有理论证明或基准。@Alvarsi。你很幸运；）这使用的是

UIImageView

，而主题启动程序要求一个带掩码的圆圈

UIImage

。UIGraphicsBeginImageContextWithOptions中的第三个参数必须是0.0，而不是1.0。因为1.0非常吸引人ugly@fnc12非常感谢。我想知道为什么结果模糊难看。我们可以对非正方形图像进行裁剪和圆化吗？不推荐使用CGPointZero，请改用：CGRect（原点：.zero，大小：imageSize）。

+ (UIImage *)circularImage:(UIImage *)image withDiameter:(NSUInteger)diameter
{
    CGRect frame = CGRectMake(0.0f, 0.0f, diameter, diameter);
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:frame];
    imageView.contentMode = UIViewContentModeScaleAspectFill;
    imageView.clipsToBounds = YES;
    imageView.image = image;
    CALayer *layer = imageView.layer;


    layer.masksToBounds = YES;

    layer.cornerRadius =MAX( imageView.frame.size.height,imageView.frame.size.width)/2;

    UIGraphicsBeginImageContextWithOptions(imageView.bounds.size,NO, [UIScreen mainScreen].scale);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [layer renderInContext:context];


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

    return roundedImage;
}

let roundImage = UIImage(named: "myImage")!.af_imageRoundedIntoCircle()

UIImageView *circleImageview=[[UIImageView alloc]init];
circleImageview.frame=CGRectMake(0,10, 80, 80)]; 
circleImageview.layer.cornerRadius=circleimagview.frame.size.height/2;
 circleImageview.userInteractionEnabled=YES;
 [self.view addSubview:circleImageview];

extension UIImage {

    var rounded: UIImage? {
        UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.main.scale)
        defer { UIGraphicsEndImageContext() }
        let bounds = CGRect(origin: .zero, size: size)
        UIBezierPath(roundedRect: bounds, cornerRadius: size.height/2.0).addClip()
        draw(in: bounds)
        return UIGraphicsGetImageFromCurrentImageContext()
    }

}