Question

我需要AlamofireImages的一点帮助。在应用程序中，点击表格视图单元格将使用内置的ImageView扩展下载并设置图像，如下所示：

func sendImageRequest(imageView: UIImageView, item: CatalogItem, isLargeImage: Bool? = false){
    let imageURL = ImageManager.URLBuilder(sku: item.sku, largeImage: isLargeImage)

    // Clear the image so that recycled images are cleared.
    imageView.image = nil

    // Create the request and add the token string to the authorization header
    var urlRequest = try! URLRequest(url: URL(string: imageURL)!)
    urlRequest.setValue("Bearer \(ImageManager.getTokenString()!)", forHTTPHeaderField: "Authorization")

    // If the token exists AND is VALID (not expired) - Get the image.
    if ImageManager.checkIfTokenExists() && ImageManager.checkTokenIsValid(){
        debugPrint("Valid token already exists. Fetching image... TableViewExtension")
        imageView.af_setImage(withURLRequest: urlRequest){ response in
            switch response.result{
            case .success(let image):
                debugPrint(response)
                debugPrint("SUCCESS")
                break
            case .failure(let error):
                debugPrint("Error: \(error)")
                debugPrint(response.response)
                break
            }
        }
    }
    // Else if the token exists AND is INVALID (expired) - Delete the old token, get a new one, and fetch the image
    else if ImageManager.checkIfTokenExists() && !ImageManager.checkTokenIsValid(){
        debugPrint("Token expired... Getting new token.")
        ImageManager.deleteToken()
        let tokenRequest = NetRequest.newTokenRequest(url: "http://\(SettingsManager.KEY_ServerURL).ziizii.io/zz/jwt/new?service=images.ziizii.io")
        tokenRequest.requestJWTToken(){
            debugPrint("Token renewed. Fetching image...")
            imageView.af_setImage(withURLRequest: urlRequest)
        }
    }
    // If the token doesn't exist, request a new one and fetch the image.
    else{
        debugPrint("Requesting new token...")
        let tokenRequest = NetRequest.newTokenRequest(url: "http://\(SettingsManager.KEY_ServerURL).ziizii.io/zz/jwt/new?service=images.ziizii.io")
        tokenRequest.requestJWTToken(){
            debugPrint("Token aquired. Fetching image...")
            imageView.af_setImage(withURLRequest: urlRequest)
        }
    }
}

所以，这部分我没问题。它工作，它将对象缓存到磁盘并设置ImageView图像。如果稍后再次点击它，它会检查图像是否在缓存中，如果是，则只需应用图像。整齐。

现在，对项目的一个新要求是让用户能够预加载每个图像并缓存它们。现在我不再使用AFI ImageView扩展，而是使用Downloader。我不确定如何让Downloader： A）缓存到磁盘和 B）当用户点击一个单元格时，让该ImageView扩展程序检查相同的缓存以查看它是否已预加载并应用该图像。

AFI足够聪明，可以在发出请求之前检查图像数据的缓存，所以我确信这是可能的。

我到目前为止下载图片的内容如下：

static var downloader = ImageDownloader.default

static func downloadImage(urlRequest: URLRequestConvertible)
{
    self.downloader.download(urlRequest) { response in
        switch response.result{
        case .success(let image): // If successful, cache the image.
            print("SUCCESS")
            break
        case .failure(let error): // If unsuccessful, remove the cached 404 response and apply a nil image.
            print("ERROR: \(response.error)")
            break
        }
    }
}

如果有人知道如何完成这个或任何有用的提示或技巧，那将是伟大的！谢谢！

将AlamofireImage响应缓存到磁盘

0 个答案: