c# - 如何在 iPhone 中显示/查找从 xamarin.ios 下载的图像？

Question

我们编写了一段代码，使用 xamarin.ios 中的 webclient 从 uri 下载图像。当我们下载图片时，它不会显示在图库/照片应用程序中，也不会显示在 iPhone 的任何其他位置。这是我的下载代码:

public void DownloadFiles()
    {
        try
        {

            var webClient = new WebClient();
            webClient.DownloadDataCompleted += (s, e) => {
                var bytes = e.Result;
                string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
                string localFilename = "downloaded.png";
                string localPath = Path.Combine(documentsPath, localFilename);

                Console.WriteLine("localPath:" + localPath);

                File.WriteAllBytes(localPath, bytes);

                // IMPORTANT: this is a background thread, so any interaction with
                // UI controls must be done via the MainThread
                InvokeOnMainThread(() => {

                   // imageView.Image = UIImage.FromFile(localPath);

                    UIAlertView alert = new UIAlertView()
                  {
                      Title = "alert title",
                      Message = "Download successfully"
                  };
                    alert.AddButton("OK");
                    alert.AddButton("Cancel");
                    alert.Show();
                });
            };

            var url = new Uri("https://www.xamarin.com/content/images/pages/branding/assets/xamagon.png");
            webClient.DownloadDataAsync(url);
        }
        catch(Exception e)
        {
            throw e;
        }
    }

Environment.GetFolderPath(Environment.SpecialFolder.Personal); 

如何找到这条路径？

Answer 1

我们在 info.plist 中添加了这些权限来解决这个问题。 “隐私 - 照片库添加使用说明”和“隐私 - 照片库使用说明”