试图将url转换为图像(得到黑色图像)- asp.net

我尝试转换url -我的代码运行了一段时间，工作完美(我怀疑这可能是特权问题)。

当我使用vs运行网站时(图像不是黑色)-但当我在iis(本地/远程)上托管网站时，我得到黑色图像。

我没有找到任何解决方案在这里或在网上，

    public WebsiteToImage(string url, string fileName, int? with, int? height)
    {
        // With file  
        m_Url = url;
        m_FileName = fileName;
        m_With = with;
        m_Height = height;
    }
    public Bitmap Generate()
    {
        // Thread  
        var m_thread = new Thread(_Generate);
        m_thread.SetApartmentState(ApartmentState.STA);
        m_thread.Start();
        m_thread.Join();
        return m_Bitmap;
    }
    private void _Generate()
    {
        var browser = new WebBrowser { ScrollBarsEnabled = false };
        browser.Navigate(m_Url);
        browser.DocumentCompleted += WebBrowser_DocumentCompleted;
        while (browser.ReadyState != WebBrowserReadyState.Complete)
        {
            Application.DoEvents();
        }
        browser.Dispose();
    }
    private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
    {
        // Capture  
        var browser = (WebBrowser)sender;
        browser.ClientSize = new Size(m_With == null ? browser.Document.Body.ScrollRectangle.Width : (int)m_With, m_Height == null ? browser.Document.Body.ScrollRectangle.Bottom : (int)m_Height);
        browser.ScrollBarsEnabled = false;
        m_Bitmap = new Bitmap(m_With == null ? browser.Document.Body.ScrollRectangle.Width : (int)m_With, m_Height == null ? browser.Document.Body.ScrollRectangle.Bottom : (int)m_Height);
        browser.BringToFront();
        browser.DrawToBitmap(m_Bitmap, browser.Bounds);
        // Save as file?  
        if (m_FileName.Length > 0)
        {
            // Save  
            m_Bitmap.SaveJPG100(m_FileName);
        }
    }
}
public static void SaveJPG100(this Bitmap bmp, string filename)
    {

        var encoderParameters = new EncoderParameters(1);
        encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);

        bmp.Save(filename, GetEncoder(ImageFormat.Jpeg), encoderParameters);

    }

m_thread.Start();
m_thread.Join();