WebImage作为TabView SwiftUI中的TabItem

Question

我试图将URL中的图像显示为TabView的tabItem。我用SDWebImageSwiftUI尝试了一下，但是那没用，所以我现在要尝试的是将图像存储在文档目录中，然后从中加载为UIImage。

这是我到目前为止编写的代码，但是没有用。但是，如果我加载系统映像，则可以正常工作。

import SwiftUI
import Alamofire
 
struct ContentView: View {
    var body: some View {
        TabView {
            VStack {
                Text("Hello")
            }
            .onAppear(perform: {
                self.saveAvatarImage(fromUrl: "https://gmsrp.cachefly.net/images/20/05/15/65e1de275864fb9c73b7be374315481a/960.jpg")
            })
            .frame(maxWidth:.infinity,maxHeight: .infinity)
            .tabItem {
                Image(uiImage: getAvatarImage() ?? UIImage.init(systemName: "star.fill")!)
                    .frame(width:20,height: 20)
            }
        }
    }
    
    func avatarFolderUrl() -> URL {
        return FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].appendingPathComponent("Avatar", isDirectory: true)
    }

    func saveAvatarImage(fromUrl url:String) {
        
        guard let avatarUrl = URL.init(string: url) else {
            return
        }
        
        DispatchQueue.global().async {

            let destination: DownloadRequest.Destination = { _, _ in
                let documentsURL = self.avatarFolderUrl()
                let fileURL = documentsURL.appendingPathComponent("avatar.jpg")
                return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
            }

            AF.download(URLRequest.init(url: avatarUrl), to: destination)
                .response { (response) in
                    switch response.result {
                    case .success:
                        let documentsURL = self.avatarFolderUrl()
                        let fileURL = documentsURL.appendingPathComponent("avatar.jpg")
                        
                        if FileManager.default.fileExists(atPath: fileURL.path) {
                            if let image = UIImage.init(contentsOfFile: fileURL.path) {
                                if let compressedImageData = image.jpegData(compressionQuality: 1.0) {
                                    try? compressedImageData.write(to: fileURL)
                                }
                            }
                        }
                    case .failure(let error):
                        debugPrint("Failed to download : \(error)")
                    }
                }
        }
    }

    func getAvatarImage() -> UIImage? {
        let documentsURL = avatarFolderUrl()
        let fileURL = documentsURL.appendingPathComponent("avatar.jpg")
        if FileManager.default.fileExists(atPath: fileURL.path) {
            if let image = UIImage.init(contentsOfFile: fileURL.path) {
                debugPrint("Loading Profile From \(fileURL.path)")
                return image
            }
        }
        return nil
    }
}

这里是上面代码的输出。它显示的是蓝色视图，而不是图像。正确的方法是加载系统映像。