我的代码在普通设备上工作正常,但在视网膜设备上产生模糊的图像。

有人知道我的问题的解决方案吗?

+ (UIImage *) imageWithView:(UIView *)view
{
    UIGraphicsBeginImageContext(view.bounds.size);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];

    UIImage * img = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return img;
}

当前回答

下面是一个基于@Dima的答案的Swift 4 UIView扩展。

extension UIView {
   func snapshotImage() -> UIImage? {
       UIGraphicsBeginImageContextWithOptions(bounds.size, isOpaque, 0)
       drawHierarchy(in: bounds, afterScreenUpdates: false)
       let image = UIGraphicsGetImageFromCurrentImageContext()
       UIGraphicsEndImageContext()
       return image
   }
}

其他回答

- (UIImage*)screenshotForView:(UIView *)view
{
    UIGraphicsBeginImageContext(view.bounds.size);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    // hack, helps w/ our colors when blurring
    NSData *imageData = UIImageJPEGRepresentation(image, 1); // convert to jpeg
    image = [UIImage imageWithData:imageData];

    return image;
}

对于Swift 5.1,你可以使用这个扩展:

extension UIView {

    func asImage() -> UIImage {
        let renderer = UIGraphicsImageRenderer(bounds: bounds)

        return renderer.image { layer.render(in: $0.cgContext) }
    }
}

在这个方法中,只需要传递一个view对象它就会返回一个UIImage对象。

-(UIImage*)getUIImageFromView:(UIView*)yourView
{
 UIGraphicsBeginImageContext(yourView.bounds.size);
 [yourView.layer renderInContext:UIGraphicsGetCurrentContext()];
 UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 return image;
}

使用现代的uigraphicsimagerender

public extension UIView {
    @available(iOS 10.0, *)
    public func renderToImage(afterScreenUpdates: Bool = false) -> UIImage {
        let rendererFormat = UIGraphicsImageRendererFormat.default()
        rendererFormat.opaque = isOpaque
        let renderer = UIGraphicsImageRenderer(size: bounds.size, format: rendererFormat)

        let snapshotImage = renderer.image { _ in
            drawHierarchy(in: bounds, afterScreenUpdates: afterScreenUpdates)
        }
        return snapshotImage
    }
}

斯威夫特3

带有UIView扩展的Swift 3解决方案(基于Dima的回答)应该是这样的:

extension UIView {
    public func getSnapshotImage() -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.bounds.size, self.isOpaque, 0)
        self.drawHierarchy(in: self.bounds, afterScreenUpdates: false)
        let snapshotImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return snapshotImage
    }
}