PAB.WebControls Webbrowser control

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C#2.0

C#

Hi,

I am using third party open source PAB.WebControls control. It is a wrapper library which allows one to navigate a URL and capture a screen shot of the URL.

I have a strange problem where if I make two sub-sequent calls to one of the method (i.e GetSiteThumbnail), the second request takes close to minute to finish. If I make one request the process finishes in timely fashen (i.e 2 to 3 seconds which is fine). I tried to search and found out that WebBrowser control of .net framework might have memory leak problem. I am not sure whether that is the issue. If someone came across a similar problem and have suggestion, please let me know.

Here is the complete source code:

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
using System.IO;
using System.Reflection;

namespace PAB.WebControls
{
    public class WebBrowserEx : WebBrowser
    {
        public WebBrowserEx()
        {
        }
        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
                case 0x021:
                case 0x201:
                case 0x204:
                case 0x207:
                    base.DefWndProc(ref m);
                    return;
            }
            base.WndProc(ref m);
        }
    }
    public class WebSiteThumbnail:SWBaseClass
    {
        private string url = null;      
        private Bitmap bmp = null;
        public Bitmap Image 
        {
            get 
            { 
                return bmp; 
            } 
        }
        private ManualResetEvent mre = new ManualResetEvent(false);
        private int timeout = 5; // this could be adjusted up or down
        private int thumbWidth;
        private int thumbHeight;
        private int width;
        private int height;
        private string absolutePath;
        private string fullfilePath;
        #region Static Methods
       
        public static Bitmap GetSiteThumbnail(string url, int width, int height, int thumbWidth, int thumbHeight, string absolutePath, string fullFilePath)
        {
            WebSiteThumbnail thumb = new WebSiteThumbnail(url, width, height, thumbWidth, thumbHeight, absolutePath, fullFilePath);
            Bitmap b = thumb.GetScreenShot();
            if (b == null)
                b = (Bitmap)System.Drawing.Image.FromStream(Assembly.GetExecutingAssembly().GetManifestResourceStream("PAB.WebControls.Notavailable.jpg"));
             return b;
        }
        #endregion
        #region Ctors
       
        public WebSiteThumbnail(string url, int width, int height, int thumbWidth, int thumbHeight,string absolutePath, string fullFilePath)
        {
            this.url = url;
            this.width = width;
            this.height = height;
            this.thumbHeight = thumbHeight;
            this.thumbWidth = thumbWidth;
            this.absolutePath = absolutePath;
            this.fullfilePath = fullFilePath;
        }
        #endregion
        #region ScreenShot
        public Bitmap GetScreenShot()//original keep this
        {
            try
            {
                log.Debug("GetScreenShot begins: ");
                //if (fullfilePath != null && File.Exists(fullfilePath))
                //{
                //    bmp = (Bitmap)System.Drawing.Image.FromFile(fullfilePath);
                //}
                //else
                //{
                    Thread t = new Thread(new ThreadStart(_GetScreenShot));
                    t.SetApartmentState(ApartmentState.STA);
                    t.Start();
                    mre.WaitOne();
                    t.Abort();
                //}
                    log.Debug("GetScreenShot ends: ");
            }
            catch (Exception ex)
            {
                log.Error("Error occured in GetScreenShot: " + ex);
                //throw;
            }
            return bmp;
        }
        
        
        #endregion
        private void _GetScreenShot() 
        {
            try
            {
                log.Debug("_GetScreenShot begins: ");
                WebBrowserEx webBrowser = new WebBrowserEx();
                webBrowser.ScriptErrorsSuppressed = true;
                webBrowser.ScrollBarsEnabled = false;
                DateTime time = DateTime.Now;
                webBrowser.Navigate(url, false); //mahesh added false on 11/16/2010 12:27pm
                webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(WebBrowser_DocumentCompleted);
                while (true)
                {
                    Thread.Sleep(0);
                    TimeSpan elapsedTime = DateTime.Now - time;
                    if (elapsedTime.Seconds >= timeout)
                    {
                        mre.Set();
                    }
                    Application.DoEvents();
                }
                log.Debug("_GetScreenShot ends: ");
            }
            catch (Exception ex)
            {
                log.Error("Error occured in _GetScreenShot: " + ex.InnerException, ex);
            }
        }

        private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) 
        {
            try
            {
                log.Debug("WebBrowser_DocumentCompleted begins: ");
                WebBrowserEx webBrowser = (WebBrowserEx)sender;
                webBrowser.ScriptErrorsSuppressed = true;
                webBrowser.ClientSize = new Size(this.width, this.height);
                webBrowser.ScrollBarsEnabled = false;
                bmp = new Bitmap(webBrowser.Bounds.Width, webBrowser.Bounds.Height);
                webBrowser.BringToFront();
                webBrowser.DrawToBitmap(bmp, webBrowser.Bounds);
                Image img = bmp.GetThumbnailImage(thumbWidth, thumbHeight, null, IntPtr.Zero);
                //if (fullfilePath != null && !File.Exists(fullfilePath)) //original 3/8/11
                //{
                //    img.Save(fullfilePath);
                //}
                img.Save(fullfilePath); //new on 3/1/11
                
                bmp = (Bitmap)img;
                webBrowser.Dispose();
                if (mre != null)
                    mre.Set();
                log.Debug("WebBrowser_DocumentCompleted ends: ");
            }
            catch (Exception ex)
            {
                log.Error("Error occured in WebBrowser_DocumentCompleted: " + ex);
                //throw; //out of bravity from Mr. Shilon, eating the error where manualresetevent is trying to synchronize the waiting between multiple threads.
            }
        }
        public void Dispose()
        {
            if (bmp != null) this.bmp.Dispose();
        }
    }
}