Generate Screenshot From WebBrowser Control

问题:

I grabbed some code from the link below to generate a screenshot from a web browser control: http://pietschsoft.com/post/2008/07/C-Generate-WebPage-Thumbmail-Screenshot-Image.aspx

Then, I modified to be an extension method like so:

public static Bitmap GetScreenshot(this WebBrowser webBrowser)
        {
            // Load the webpage into a WebBrowser control
            using (WebBrowser wb = new WebBrowser())
            {
                wb.ScrollBarsEnabled = false;
                wb.ScriptErrorsSuppressed = true;
                wb.Navigate(webBrowser.Url);
                while (wb.ReadyState != WebBrowserReadyState.Complete)
                {
                    Application.DoEvents();
                }

                // Set the size of the WebBrowser control
                wb.Width = wb.Document.Body.ScrollRectangle.Width;
                wb.Height = wb.Document.Body.ScrollRectangle.Height;

                // Get a Bitmap representation of the webpage as it's rendered in the WebBrowser control
                Bitmap bitmap = new Bitmap(wb.Width, wb.Height);
                wb.DrawToBitmap(bitmap, new Rectangle(0, 0, wb.Width, wb.Height));

                return bitmap;
            }
        }

It works great for most web pages, but I am trying to use it for a SharePoint site and the image is coming out as 250x250 every time. :-s

Any geniuses here that can give me a solution?

Thanks in advance

回答1:

Well, the reason for this seems to be that my new WebBrowser (wb) is uninitialized even after I call Navigate(). The Url property shows as null. This is weird. Does it mean I cannot create a WebBrowser in code and never display it? It would be a shame to have to display the thing. :-(

回答2:

You can check that question taking-screenshot-of-a-webpage-programmatically.
It is based on this webpage_thumbnailer which uses Web Browser control.

回答3:

For one, the DrawToBitmap class does not exist under the webbrowser control. I suggest using CopyFromScreen. Here is a code snippet:

    Bitmap b = new Bitmap(wb.ClientSize.Width, webBrowser1.ClientSize.Height);
    Graphics g = Graphics.FromImage(b);
    g.CopyFromScreen(this.PointToScreen(wb.Location), new Point(0, 0), wb.ClientSize);
    //The bitmap is ready. Do whatever you please with it!
    b.Save(@"c:\screenshot.jpg", ImageFormat.Jpeg);
    MessageBox.Show("Screen Shot Saved!");