using System.IO;

using System.Drawing;

using System.Threading;

using System.Windows.Forms;

public class WebSiteThumbnail

{

    Bitmap m_Bitmap;

    string m_Url;

    int m_BrowserWidth, m_BrowserHeight, m_ThumbnailWidth, m_ThumbnailHeight;

    public WebSiteThumbnail(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)

    {

        m_Url = Url;

        m_BrowserHeight = BrowserHeight;

        m_BrowserWidth = BrowserWidth;

        m_ThumbnailWidth = ThumbnailWidth;

        m_ThumbnailHeight = ThumbnailHeight;

    }

    public static Bitmap GetWebSiteThumbnail(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)

    {

        WebSiteThumbnail thumbnailGenerator = new WebSiteThumbnail(Url, BrowserWidth, BrowserHeight, ThumbnailWidth, ThumbnailHeight);

        return thumbnailGenerator.GenerateWebSiteThumbnailImage();

    }

    public Bitmap GenerateWebSiteThumbnailImage()

    {

        Thread m_thread = new Thread(new ThreadStart(_GenerateWebSiteThumbnailImage));

        m_thread.SetApartmentState(ApartmentState.STA);

        m_thread.Start();

        m_thread.Join();

        return m_Bitmap;

    }

    private void _GenerateWebSiteThumbnailImage()

    {

        WebBrowser m_WebBrowser = new WebBrowser();

        m_WebBrowser.ScrollBarsEnabled = false;

        m_WebBrowser.Navigate(m_Url);

        m_WebBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(WebBrowser_DocumentCompleted);

        while (m_WebBrowser.ReadyState != WebBrowserReadyState.Complete)

            Application.DoEvents();

        m_WebBrowser.Dispose();

    }

    private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)

    {

        WebBrowser m_WebBrowser = (WebBrowser)sender;

        m_WebBrowser.ClientSize = new Size(this.m_BrowserWidth, this.m_BrowserHeight);

        m_WebBrowser.ScrollBarsEnabled = false;

        m_Bitmap = new Bitmap(m_WebBrowser.Bounds.Width, m_WebBrowser.Bounds.Height);

        m_WebBrowser.BringToFront();

        m_WebBrowser.DrawToBitmap(m_Bitmap, m_WebBrowser.Bounds);

        m_Bitmap = (Bitmap)m_Bitmap.GetThumbnailImage(m_ThumbnailWidth, m_ThumbnailHeight, null, IntPtr.Zero);

    }

}

    Bitmap m_Bitmap = WebSiteThumbnail.GetWebSiteThumbnail("这里是html的连接地址", , , , );

    MemoryStream ms = new MemoryStream();

    m_Bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);//JPG、GIF、PNG等均可

    byte[] buff = ms.ToArray();

    Response.BinaryWrite(buff);

    System.Drawing.Image img = byteArrayToImage(buff);

    string url = "图片保存路径.png";

    img.Save(HttpContext.Current.Server.MapPath(url));