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HTML5 发布时间：2022-04-27 发布网站：大佬教程 code.js-code.com

大佬教程收集整理的这篇文章主要介绍了ios – 如果尚未缓存,如何使用SDWebImageManager下载图像？，大佬教程大佬觉得挺不错的，现在分享给大家，也给大家做个参考。

我需要SDWeb @L_694_0@manager的完成处理程序功能(将下载或缓存的图像设置为黑白),所以我使用它而不是sd_setimage.我的问题是我无法弄清楚如何使用SDWebImageManager下载或获取图像的缓存版本.每次tableview单元格出列并重新加载时,图像都会重新下载.我尝试过设置选项：SDWebImageDownloaderOptionS.UseNSURLCache,但无济于事.任何建议将不胜感激！这是我的代码：

SDWebImageManager.shared().imageDownloader?.downloadImage(with:URL(String: imgurL),options: SDWebImageDownloaderOptionS.UseNSURLCache,progress: nil,completed: { (image,error,cacheType,url) in 
   if image != nil {
      let beginImage = CIImage(image: image!)
      let blackNwhiteImg = beginImage?.applyingFilter("CIColorControls",withInputParameters: [kCIInputSaturationKey:0.0])
      let newImage = UIImage(ciImage: blackNwhiteImg!)
      cell.button.setImage(newImage,for: .normal)
   }
})

解决方法

从缓存中提取的更新答案：

SDWebImageManager.shared().loadImage(with: URL?,options: SDWebImageOptions,progress: { (Int,Int,URL?) in
    code
},completed: { (UIImage?,Data?,Error?,SDImageCacheType,Bool,URL?) in
    code
})

为了便于参考,我将在此屏幕截图中显示XCode在输入功能时显示的注释：

此外,SDWebImageManager文件中包含的注释：

/**
 * Downloads the image at the given URL if not present in cache or return the cached version otherwise.
 *
 * @param url            The URL to the image
 * @param options        A mask to specify options to use for this request
 * @param progressBlock  A block called while image is downloading
 *                       @note the progress block is executed on a BACkground queue
 * @param completedBlock A block called when operation has been completed.
 *
 *   This parameter is required.
 * 
 *   This block has no return value and takes the requested UIImage as first parameter and the NSData representation as second parameter.
 *   In case of error the image parameter is nil and the third parameter may contain an NSError.
 *
 *   The forth parameter is an `SDImageCacheType` enum inDicaTing if the image was retrieved from the local cache
 *   or from the memory cache or from the network.
 *
 *   The fith parameter is set to NO when the SDWebImageProgressiveDownload option is used and the image is
 *   downloading. This block is thus called repeatedly with a partial image. When image is fully downloaded,the
 *   block is called a last time with the full image and the last parameter set to YEs.
 *
 *   The last parameter is the original image URL
 *
 * @return Returns an NSObject conforming to SDWebImageOperation. Should be an instance of SDWebImageDownloaderOperation