Drawing a WebBrowser control to a bitmap - vb.net

Question

I'm trying to save a panel control as a bitmap using the following code (VB.net):
Private Sub SaveFileDialog1_FileOk(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles SaveFileDialog1.FileOk
filename = SaveFileDialog1.FileName
Dim CardImg As New Bitmap(Panel1.Width, Panel1.Height)
Panel1.DrawToBitmap(CardImg, Panel1.ClientRectangle)
CardImg.Save(filename, System.Drawing.Imaging.ImageFormat.Bmp)
End Sub
Everything works, except the Web browser control, which is docked in the panel. In the saved bitmap, this control appears as only white space, while everything else in the panel renders out fine. Any ideas?

Answer 1

When I saved snapshots from a WebBrowser I called .Focus() on it after navigating -- and somehow the white picture results magically disapperard. Don't know why, but it worked for me.

Answer 2

Download "ScreenCapture.vb" from http://www.vbforums.com/showthread.php?t=385497,
use CaptureDeskTopRectangle but you should not use the location of your panel because it's
referenced to panel parent you should use yourpanel.PointToScreen() to identify the correct
rectangle.
Regards..
UPDATE:
Check this out, you gon like it, i similute your case and it's working:
Private Sub btnBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBrowse.Click
Try
Using fl As New SaveFileDialog
fl.Filter = "PNG images|*.png"
If fl.ShowDialog = Windows.Forms.DialogResult.OK Then
Dim sc As New screencapture
Dim pt = WebBrowser1.Parent.PointToScreen(WebBrowser1.Location)
Dim rec As New Rectangle(pt.X, pt.Y, WebBrowser1.Width, WebBrowser1.Height)
Application.DoEvents()
Threading.Thread.Sleep(500)
Using bmp As Bitmap = sc.CaptureDeskTopRectangle(rec, WebBrowser1.Width, WebBrowser1.Height)
bmp.Save(fl.FileName, System.Drawing.Imaging.ImageFormat.Png)
End Using
End If
End Using
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Update 2:
In Form:
Private Sub btnBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBrowse.Click
Try
Using fl As New SaveFileDialog
fl.Filter = "PNG images|*.png"
If fl.ShowDialog = Windows.Forms.DialogResult.OK Then
JSsetTimeout.SetTimeout(Me, "TakeShot", 1500, fl.FileName)
End If
End Using
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Sub TakeShot(ByVal FilePath As String)
Try
Application.DoEvents()
Dim sc As New screencapture
Dim pt = WebBrowser1.Parent.PointToScreen(WebBrowser1.Location)
Dim rec As New Rectangle(pt.X, pt.Y, WebBrowser1.Width, WebBrowser1.Height)
Using bmp As Bitmap = sc.CaptureDeskTopRectangle(rec, WebBrowser1.Width, WebBrowser1.Height)
bmp.Save(FilePath, System.Drawing.Imaging.ImageFormat.Png)
End Using
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
To Create a time delay add the class below :
Public Class JSsetTimeout
Public res As Object = Nothing
Dim WithEvents tm As Timer = Nothing
Dim _MethodName As String
Dim _args() As Object
Dim _ClassInstacne As Object = Nothing
Public Shared Sub SetTimeout(ByVal ClassInstacne As Object, ByVal obj As String, ByVal TimeSpan As Integer, ByVal ParamArray args() As Object)
Dim jssto As New JSsetTimeout(ClassInstacne, obj, TimeSpan, args)
End Sub
Public Sub New(ByVal ClassInstacne As Object, ByVal obj As String, ByVal TimeSpan As Integer, ByVal ParamArray args() As Object)
If obj IsNot Nothing Then
_MethodName = obj
_args = args
_ClassInstacne = ClassInstacne
tm = New Timer With {.Interval = TimeSpan, .Enabled = False}
AddHandler tm.Tick, AddressOf tm_Tick
tm.Start()
End If
End Sub
Private Sub tm_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles tm.Tick
tm.Stop()
RemoveHandler tm.Tick, AddressOf tm_Tick
If Not String.IsNullOrEmpty(_MethodName) AndAlso _ClassInstacne IsNot Nothing Then
res = CallByName(_ClassInstacne, _MethodName, CallType.Method, _args)
Else
res = Nothing
End If
End Sub
End Class