根据网络URL地址转换图片

代码如下：

void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
    string imgURL = "http://www.***.com/***.jpg";
    if (!String.IsNullOrEmpty(imgURL))
    {
        Application.Current.Dispatcher.BeginInvoke(new Action(() =>
            {
                //return byte[].
                byte[] content = this.GetImageContent(imgURL);

                //return bitmap source.
                BitmapSource bitmapSource = ConvertToImage(content);

                this.MyImg.Source = bitmapSource;
            }), DispatcherPriority.Background);
    }
}

#region GetImage

private byte[] GetImageContent(string imgURL)
{ 
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(imgURL);
    request.AllowAutoRedirect = true;
 
    WebProxy proxy = new WebProxy();
    proxy.BypassProxyOnLocal = true;
    proxy.UseDefaultCredentials = true; 
    request.Proxy = proxy;
 
    WebResponse response = request.GetResponse();
 
    using (Stream stream = response.GetResponseStream())
    {
        using (MemoryStream memoryStream = new MemoryStream())
        {
            Byte[] buffer = new Byte[1024];
            int current = 0;
            while ((current = stream.Read(buffer, 0, buffer.Length)) != 0)
            {
                memoryStream.Write(buffer, 0, current);
            }
            return memoryStream.ToArray();
        }
    }
}

private BitmapSource ConvertToImage(byte[] content)
{
    using (MemoryStream memoryStream = new MemoryStream(content))
    {
        Bitmap bitmap = new Bitmap(memoryStream);
        IntPtr bmpPt = bitmap.GetHbitmap();
        BitmapSource bitmapSource = Imaging.CreateBitmapSourceFromHBitmap(
                            bmpPt,
                            IntPtr.Zero,
                            Int32Rect.Empty,
                            BitmapSizeOptions.FromEmptyOptions());
        return bitmapSource;
    }
}
 
#endregion