image - 从 url 创建 imagebrush、位图和 writeablebitmap

Question

嘿，我有一个使用 silverlight API 的 Windows Phone 8.1 应用程序。我正在从我的 blob 存储中下载此图像。

该图像来自这样的链接:https://[service].blob.core.windows.net/[imagename].png只需使用 URI，即可在多个浏览器中显示和下载图像。

我现在想将其用作基于 blobstorage 中的 imageuri 的图像画笔:

// If we have a returned SAS.
                BitmapImage myOnlineImage = new BitmapImage();
                myOnlineImage.UriSource = new Uri(uploadImage.ImageUri, UriKind.RelativeOrAbsolute);
                //ImageOnlineTest.Source = myOnlineImage;
                var imageBrush = new ImageBrush
                {
                    ImageSource = myOnlineImage,
                    Stretch = Stretch.None
                };
                var source = FindChildShieldCanvas(CanvasImage, imageBrush);

                WriteableBitmap wbm = new WriteableBitmap((BitmapImage)myOnlineImage);
                ImageOnlineTest.Source = wbm;

myOnlineImage 未正确创建，至少我无法将图像转换为 writeablebitmapimage(从转换中获得 null 异常)，此外 imagebrush 为空，即 null。但据我所知这是这样做的方法吗？

基本上

如何根据 https 站点的 URL 创建 imagebrush？

Answer 1

我最终自己解决了这个问题:

记住添加using System.Runtime.InteropServices.WindowsRuntime;

// If we have a returned SAS.
                BitmapImage myOnlineImage = new BitmapImage();

                //myOnlineImage.UriSource = new Uri(uploadImage.ImageUri, UriKind.RelativeOrAbsolute);
                using (var webCLient = new Windows.Web.Http.HttpClient())
                {
                    webCLient.DefaultRequestHeaders.Add("User-Agent", "bot");
                    var responseStream = await webCLient.GetBufferAsync(new Uri(uploadImage.ImageUri, UriKind.RelativeOrAbsolute));
                    var memoryStream = new MemoryStream();//responseStream.ToArrayAsStream().ReadAsync());

                    memoryStream.Write(responseStream.ToArray(), 0, responseStream.ToArray().Length);
                    memoryStream.Position = 0;
                    myOnlineImage.SetSource(memoryStream);

                }
                //ImageOnlineTest.Source = myOnlineImage;
                var imageBrush = new ImageBrush
                {
                    ImageSource = myOnlineImage,
                    Stretch = Stretch.None
                };
                var source = FindChildShieldCanvas(CanvasImage, imageBrush);

                WriteableBitmap wbm = new WriteableBitmap((BitmapImage)myOnlineImage);

此代码适用于 imagebrush 和 writeablebitmap