Question

我想使用以下代码将内容模式的角半径设置为宽高比：

  cell.imgvAlbum.contentMode = UIViewContentModeScaleAspectFit;
  cell.imgvAlbum.clipsToBounds = YES;
  cell.imgvAlbum.layer.cornerRadius  = 5.0f;

但我只是为内容模式获取输出，因为方面适合。我也尝试过：

  cell.imgvAlbum.layer.masksToBounds  = YES;

角落半径怎么办？请给我一些解决方案。提前谢谢。

Answer 1

使用以下方法获取圆角的指定半径的圆角图像，将上述所有属性应用为UIViewContentModeScaleAspectFit，剪切到边界e.t.c.在图像视图上，通过在图像视图上调用下面的函数来设置接收的图像。

-(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;
}

呼叫

  UIImage *image = [self makeRoundedImage:[UIImage imageNamed:@"accept~iphone"]
                    radius: 5.0f];

  cell.imgvAlbum.contentMode = UIViewContentModeScaleAspectFit;
  cell.imgvAlbum.clipsToBounds = YES;
  cell.imgvAlbum.layer.cornerRadius  = 5.0f;

  cell.imgvAlbum.layer.masksToBounds  = YES;

  [cell.imgvAlbum setImage: image];

Answer 2

使用UIViewContentModeScaleAspectFit时，图像并不总是填充ImageView的框架，这就是您无法看到角半径的原因。

尝试将背景颜色添加到imageView，您将看到角半径正在工作。

如果您想在任何情况下查看圆角，您应该使用其他内容模式，例如aspectFill或scaleToFill。例如：

cell.imgvAlbum.contentMode = UIViewContentModeScaleAspectFill;

另一种选择是增加放在imageView中的图像的大小或减小imageView的大小。

Answer 3

UIImageView Corner Radius only Top left and Right in iOS

UIBezierPath *maskPath;
        maskPath = [UIBezierPath bezierPathWithRoundedRect:imageLayer.bounds
                                         byRoundingCorners:(UIRectCornerTopLeft|UIRectCornerTopRight)
                                               cornerRadii:CGSizeMake(10.0, 10.0)];

        CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
        maskLayer.frame = self.bounds;
        maskLayer.path = maskPath.CGPath;
        imageLayer.mask = maskLayer;

Answer 4

快速版本作为扩展实用程序：

extension UIImage {

/**
 - Parameter cornerRadius: The radius to round the image to.
 - Returns: A new image with the specified `cornerRadius`.
 **/
func roundedImage(cornerRadius: CGFloat) -> UIImage? {
    let size = self.size

    // create image layer
    let imageLayer = CALayer()
    imageLayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
    imageLayer.contents = self.cgImage

    // set radius
    imageLayer.masksToBounds = true
    imageLayer.cornerRadius = cornerRadius

    // get rounded image
    UIGraphicsBeginImageContext(size)
    if let context = UIGraphicsGetCurrentContext() {
        imageLayer.render(in: context)
    }
    let roundImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return roundImage
}

用法-不要忘记在imageView上重新设置新图像：

switch self.imageContentMode {
case .scaleAspectFit:
    // round actual image if aspect fit
    self.image = self.image?.roundedImage(cornerRadius: radius)
    self.imageView?.image = self.image

default:
    // round image view corners
    self.imageView?.roundCorners(radius: radius)
}

iOS：图像视图方面适合角半径

4 个答案: