c# - 如何在单击时捕获图像的 URL 并将图像保存在使用 silverlight 的隔离存储中

Question

从网站单击图像后，我想在任何容器中捕获并保存图像的 URL，然后将图像保存在隔离存储中。

有没有人可以为此提供代码？

谢谢

Answer 1

要下载图像，您需要获取 URI。一旦你得到它，它非常简单：

 public class ServiceImageDownloader
{
    private readonly BitmapImage _downloadedBmpImage = new BitmapImage();

    public ServiceImageDownloader()
    {
        _downloadedBmpImage.ImageOpened += DownloadedBmpImageImageOpened;
        _downloadedBmpImage.ImageFailed += DownloadedBmpImageImageFailed;
        _downloadedBmpImage.CreateOptions = BitmapCreateOptions.BackgroundCreation;
    }

    public void DownloadImage(string imageUri)
    {
      _downloadedBmpImage.UriSource = imageUri;
    }

    private void DownloadedBmpImageImageOpened(object sender, RoutedEventArgs e)
    {
        try
        {
            OnImageDownloaded(new WriteableBitmap(_downloadedBmpImage));
        }
        catch
        {
            //manage other classic errors
        }
    }

    private void OnImageDownloaded(WriteableBitmap wbImTemp)
    {
        //here you get your image as a writeableBmp and you can do whatever you wish,
        //as save it in your IS in your example
    }
}

现在对于 IS，我建议您将您的图像用作流或可序列化的对象。它可能是这样的：

 public bool WriteImage(string imageName, Stream streamImage)
    {
        IsolatedStorageFile store = null;
        Stream stream = null;

        try
        {

            using (store = IsolatedStorageFile.GetUserStoreForSite())
            {                    
                // Open/Create the file for writing
                stream = new IsolatedStorageFileStream(imageName,
                    FileMode.Create, FileAccess.Write, store);

                streamImage.CopyTo(stream);

                stream.Close();
                streamImage.Close();
            }
            return true;

        }
        catch (Exception ie)
        {
           //manage error the way you prefer (think especially to quota management)
        }
    }

希望能帮助到你。