如何在Swift中显示SDWebimage作为背景色

Question

SDWebImage是用于将URL转换为图像的出色库。 它的工作很棒。 但是，我有以下问题

//对于imageview，我们设置为

 eventImageView.sd_setImage(with: URL(string: imageUrl), placeholderImage: UIImage(named: "placeholder.png")) // but, for Image as UIColor, Showing compiler error if I use like following self.scrollView.backgroundColor = UIColor(patternImage: sd_setImage(with: URL(string: imageUrl), placeholderImage:UIImage(named: "placeholder.png"))) 

甚至我也尝试跟随

  let imageBG = sd_setImage(with: URL(string: image), placeholderImage: UIImage(named: "placeholder.png")) self.scrollView.backgroundColor = UIColor(patternImage: imageBG) 

及其显示以下错误

使用未解析的标识符“ sd_setImage”

谁能建议我解决此问题？

Answer 1

首先需要使用SDWebImageManager下载图像，然后在UIColor(patterImage:)构造函数中使用它。 请尝试以下代码：

 SDWebImageManager.shared().loadImage(with: URL(string: imageUrl), options: [], progress: nil, completed: { (image, data, error, cacheType, success, url) in
                    DispatchQueue.main.async {
                        guard let image = image else {                            
                            return
                        }
                        self.scrollView.backgroundColor = UIColor(patternImage: image)
                    }
                })

Answer 2

发生这种情况是因为sd_setImage是一个UIImageView方法（ eventImageView应该是UIImageView ）， init（patternImage :)声明是：

init(patternImage image: UIImage)

这意味着patternImage参数是UIImage 而不是 UIImageView 。

为了解决这个问题，你应该首先加载图像视图，一旦装做你可以指定颜色是image的图像视图：

eventImageView.sd_setImage(with: URL(string: imageUrl), placeholderImage: UIImage(named: "placeholder.png")) { (image, error, cache, url) in
      self.scrollView.backgroundColor = UIColor(patternImage: image)
}

或（不带占位符）：

eventImageView.sd_setImage(with: URL(string: imageUrl)) { (image, error, cache, url) in
      self.scrollView.backgroundColor = UIColor(patternImage: image)
}

Answer 3

sd_setImage(with适用于UIImageView

将结构创建为-

  struct ImageSetter {
        static func setImage(scrollView: UIScrollView,myImageView: UIImageView,imageUrl: URL,placeHolderImage: UIImage){
            myImageView.sd_setImage(with: imageUrl, placeholderImage: placeHolderImage, options: [], completed: { (imageBackground, error, cache, url) in
                scrollView.backgroundColor = UIColor.init(patternImage: imageBackground ?? UIImage(named: "place-holder-image")!)
            })
        }
    }

采用 -

ImageSetter.setImage(scrollView: scrollView, myImageView: testImageView, imageUrl: url, placeHolderImage: image)

SDWebImage