C# 从web下载图像并存储在媒体库中（windows phone 8）

我正在尝试从网上下载一张图片，并将其保存在媒体库中，下面是我的代码，我是否遗漏了一些内容，提前谢谢

  public void storePicture()
    {
        try
        {


            using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
            {

                 string url = @"http://mynokiablog.com/wp-content/uploads/2012/11/wp8.jpeg";

                  BitmapImage storeimage = new BitmapImage(new Uri(url));

                  // height and width are 0 
                  int testheight = storeimage.PixelHeight;
                  int testwidth = storeimage.PixelWidth;
                IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile("testname");
                  // NullRefrenceException
                WriteableBitmap wb = new WriteableBitmap(storeimage);

                wb.SaveJpeg(fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
                fileStream.Close();
            }

        }
        catch (Exception ex)
        {
               System.Diagnostics.Debug.WriteLine(ex.Message);
        }

    }

你可以试试：

希望这有帮助。

您可以试试：

private void LoadIMG()
    {

        var bitmapImage = new BitmapImage { CreateOptions = BitmapCreateOptions.None };


        bitmapImage.ImageOpened += bitmapImage_ImageOpened;
        bitmapImage.ImageFailed += bitmapImage_ImageFailed;
        bitmapImage.DownloadProgress += bitmapImage_DownloadProgress;
        bitmapImage.UriSource = new Uri("http://ds.serving-sys.com/BurstingRes///Site-16990/Type-0/7b912e70-352a-454f-8ea7-5d5ecd6ebfae.gif");
    }

    private void bitmapImage_DownloadProgress(object sender, DownloadProgressEventArgs e)
    {

    }

    private void bitmapImage_ImageFailed(object sender, ExceptionRoutedEventArgs e)
    {

    }

    private void bitmapImage_ImageOpened(object sender, RoutedEventArgs e)
    {
         var userStoreForApplication = IsolatedStorageFile.GetUserStoreForApplication(); 
         var writeableBitmap = new WriteableBitmap(sender as BitmapImage);
         var isolatedStorageFileStream = userStoreForApplication.CreateFile("Myfile.gif");
         writeableBitmap.SaveJpeg(isolatedStorageFileStream, writeableBitmap.PixelWidth, writeableBitmap.PixelHeight, 0, 85); 
    }

---

希望这有帮助。

添加事件处理程序，如下所示

private void LoadIMG()
    {

        var bitmapImage = new BitmapImage { CreateOptions = BitmapCreateOptions.None };


        bitmapImage.ImageOpened += bitmapImage_ImageOpened;
        bitmapImage.ImageFailed += bitmapImage_ImageFailed;
        bitmapImage.DownloadProgress += bitmapImage_DownloadProgress;
        bitmapImage.UriSource = new Uri("http://ds.serving-sys.com/BurstingRes///Site-16990/Type-0/7b912e70-352a-454f-8ea7-5d5ecd6ebfae.gif");
    }

    private void bitmapImage_DownloadProgress(object sender, DownloadProgressEventArgs e)
    {

    }

    private void bitmapImage_ImageFailed(object sender, ExceptionRoutedEventArgs e)
    {

    }

    private void bitmapImage_ImageOpened(object sender, RoutedEventArgs e)
    {
         var userStoreForApplication = IsolatedStorageFile.GetUserStoreForApplication(); 
         var writeableBitmap = new WriteableBitmap(sender as BitmapImage);
         var isolatedStorageFileStream = userStoreForApplication.CreateFile("Myfile.gif");
         writeableBitmap.SaveJpeg(isolatedStorageFileStream, writeableBitmap.PixelWidth, writeableBitmap.PixelHeight, 0, 85); 
    }

    storeimage.ImageOpened += bitmapImage_ImageOpened;
    storeimage.ImageFailed += bitmapImage_ImageFailed;
    storeimage.DownloadProgress += bitmapImage_DownloadProgress;

---

然后在bitmapImage_DownloadProgress中，创建可写位图并保存，添加事件处理程序，如下所示

    storeimage.ImageOpened += bitmapImage_ImageOpened;
    storeimage.ImageFailed += bitmapImage_ImageFailed;
    storeimage.DownloadProgress += bitmapImage_DownloadProgress;

---

然后在bitmapImage_DownloadProgress中，创建可写位图并保存

Hi lumen我不想使用webclient，我已使用BitmapImageHi lumen发布解决方案我不想使用webclient，我已使用bitmapImage发布解决方案