Question

I want to generate a preview thumbnail image of a web page using the link for the page. How can i do this? I’m comfortable with C#.NET, Javascript/JQuery.

Regards
NLV

Answer 1

Place an Image control in you webpage and set the ImageUrl to the snapshot.aspx page. NOw you can set some querystring options for the page.

snapshot.aspx?site=www.google.come&width=100&height=80&capWidth=800&capHeight=600

site    This tells the page which site to capture
width   width of the thumnail
height  height of the thumbnail
capWidth    What Width should the Site capture be (the thumbnail is based on this size)
capHeight   What Height should the Site capture be.    

And here is the code

    using System;
    using System.Data;
    using System.Configuration;
    using System.Collections;
    using System.Web;
    using System.Web.Security;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.WebControls.WebParts;
    using System.Web.UI.HtmlControls;
    using System.Windows.Forms;
    using System.Drawing;
    using System.Drawing.Imaging;
    using System.Threading;

public partial class snapshot : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string url = ((string.IsNullOrEmpty(Request.Params["site"])) ? "www.google.com":Request.Params["site"]);
        int width = ((string.IsNullOrEmpty(Request.Params["width"])) ? 200 : int.Parse(Request.Params["width"]));
        int height = ((string.IsNullOrEmpty(Request.Params["height"])) ? 140 : int.Parse(Request.Params["height"]));
        int capWidth = ((string.IsNullOrEmpty(Request.Params["capWidth"])) ? 800 : int.Parse(Request.Params["capWidth"]));
        int capHeight = ((string.IsNullOrEmpty(Request.Params["capHeight"])) ? 600 : int.Parse(Request.Params["capHeight"]));

        string address = "http://" + url;
        Bitmap thumbnail = WebsiteThumbnailImageGenerator.GetWebSiteThumbnail(address, capWidth, capHeight, width, height);

        Response.ContentType = "image/jpeg";
        thumbnail.Save (Response.OutputStream, ImageFormat.Jpeg); 
    }
}

public class WebsiteThumbnailImageGenerator
{
    public static Bitmap GetWebSiteThumbnail(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)
    {
        WebsiteThumbnailImage thumbnailGenerator = new WebsiteThumbnailImage(Url, BrowserWidth, BrowserHeight, ThumbnailWidth, ThumbnailHeight);
        return thumbnailGenerator.GenerateWebSiteThumbnailImage();
    }

    private class WebsiteThumbnailImage
    {
        public WebsiteThumbnailImage(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)
        {
            this.m_Url = Url;
            this.m_BrowserWidth = BrowserWidth;
            this.m_BrowserHeight = BrowserHeight;
            this.m_ThumbnailHeight = ThumbnailHeight;
            this.m_ThumbnailWidth = ThumbnailWidth;
        }

        private string m_Url = null;
        public string Url
        {
            get
            {
                return m_Url;
            }
            set
            {
                m_Url = value;
            }
        }

        private Bitmap m_Bitmap = null;
        public Bitmap ThumbnailImage
        {
            get
            {
                return m_Bitmap;
            }
        }

        private int m_ThumbnailWidth;
        public int ThumbnailWidth
        {
            get
            {
                return m_ThumbnailWidth;
            }
            set
            {
                m_ThumbnailWidth = value;
            }
        }

        private int m_ThumbnailHeight;
        public int ThumbnailHeight
        {
            get
            {
                return m_ThumbnailHeight;
            }
            set
            {
                m_ThumbnailHeight = value;
            }
        }

        private int m_BrowserWidth;
        public int BrowserWidth
        {
            get
            {
                return m_BrowserWidth;
            }
            set
            {
                m_BrowserWidth = value;
            }
        }

        private int m_BrowserHeight;
        public int BrowserHeight
        {
            get
            {
                return m_BrowserHeight;
            }
            set
            {
                m_BrowserHeight = value;
            }
        }

        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);
        }
    }
}