[RESOLVED] Text Rich Text Box not showing when saving panel content as Image

[OmariCelestine]

Hello,

Currently, I am using the code below to save the contents on a panel as an image. The thing is, all contents except for the text in the rich textbox is being saved. Can anyone help me out?

Declare Auto Function SendMessage Lib "user32" ( _
ByVal hWnd As IntPtr, _
ByVal Msg As Integer, _
ByVal wParam As IntPtr, _
ByVal lParam As Integer) As Integer
Private Enum EDrawingOptions As Integer
PRF_CHECKVISIBLE = &H1
PRF_NONCLIENT = &H2
PRF_CLIENT = &H4
PRF_ERASEBKGND = &H8
PRF_CHILDREN = &H10
PRF_OWNED = &H20
End Enum

Private Function PrintPanel()
Const WM_PRINT As Integer = &H317

Dim myBmp As Bitmap
Dim myGraphics As Graphics
Dim hdc As System.IntPtr

myBmp = New Bitmap( _
Me.pnlContent.DisplayRectangle.Width + pnlContent.Padding.Left + pnlContent.Padding.Right, _
Me.pnlContent.DisplayRectangle.Height + pnlContent.Padding.Top + pnlContent.Padding.Bottom)

myGraphics = Graphics.FromImage(myBmp)
myGraphics.DrawRectangle(Pens.White, New Rectangle(0, 0,
Me.pnlContent.DisplayRectangle.Width + pnlContent.Padding.Left + pnlContent.Padding.Right * 2, Me.pnlContent.DisplayRectangle.Height + pnlContent.Padding.Top + pnlContent.Padding.Bottom * 2))
hdc = myGraphics.GetHdc
'"FormsDispPanel" is your PAnel to print
Call SendMessage(pnlContent.Handle, WM_PRINT, hdc, _
EDrawingOptions.PRF_CHILDREN Or _
EDrawingOptions.PRF_CLIENT Or _
EDrawingOptions.PRF_NONCLIENT Or _
EDrawingOptions.PRF_OWNED)

myGraphics.ReleaseHdc(hdc)

myBmp.Save(My.Computer.FileSystem.SpecialDirectories.MyDocuments & "\out.png")

myGraphics.Dispose()
myGraphics = Nothing

myBmp = Nothing

Return True
End Function

Friend WithEvents prntDoc As New PrintDocument()

Private Sub prntDoc_PrintPage(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles prntDoc.PrintPage
e.Graphics.DrawImage(Me.PictureBox1.Image, 0, 0)
End Sub

Thanks in Advance!

[Edgemeal]

Currently, I am using the code below to save the contents on a panel as an image. The thing is, all contents except for the text in the rich textbox is being saved. Can anyone help me out?

I was going to suggest using DrawToBitmap but after testing I noticed the text in RichTextBox isn't captured with that either!
If the panel control isn't going to be covered by other windows maybe try CopyFromScreen, something like...

Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim b As Bitmap = CaptureControl(Panel1) ' capture panel area
        b.Save("M:\CapturePanel.png", Imaging.ImageFormat.Png) ' save to file
        PictureBox1.Image = b                    ' display in pic box
    End Sub

    Private Shared Function CaptureControl(ByVal control As Control) As Bitmap
        Dim bmp As Bitmap = New Bitmap(control.ClientSize.Width, control.ClientSize.Height)
        Using gr As Graphics = Graphics.FromImage(bmp)
            gr.CopyFromScreen(control.PointToScreen(control.ClientRectangle.Location), Point.Empty, control.ClientSize)
        End Using
        Return bmp
    End Function

End Class

[dunfiddlin]

I haven't done any work on it so treat this merely as a crazy idea but might it be possible to use the RichTextBoxPrintCtrl, directing output to a bitmap rather than a print document?

[OmariCelestine]

I was going to suggest using DrawToBitmap but after testing I noticed the text in RichTextBox isn't captured with that either!
If the panel control isn't going to be covered by other windows maybe try CopyFromScreen, something like...

Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim b As Bitmap = CaptureControl(Panel1) ' capture panel area
        b.Save("M:\CapturePanel.png", Imaging.ImageFormat.Png) ' save to file
        PictureBox1.Image = b                    ' display in pic box
    End Sub

    Private Shared Function CaptureControl(ByVal control As Control) As Bitmap
        Dim bmp As Bitmap = New Bitmap(control.ClientSize.Width, control.ClientSize.Height)
        Using gr As Graphics = Graphics.FromImage(bmp)
            gr.CopyFromScreen(control.PointToScreen(control.ClientRectangle.Location), Point.Empty, control.ClientSize)
        End Using
        Return bmp
    End Function

End Class

The code works but one of my panels are scrollable in which it only saves an image of the visible area of the panel.

[Edgemeal]

The code works but one of my panels are scrollable in which it only saves an image of the visible area of the panel.

Never did it but some ideas,
Draw every control using DrawToBitmap to a bitmap, but then you'd still have the same problem with the RichTextBox control.

Or use CopyFromScreen like above but temporarily resize the scrollable control so everything inside it is viewable (painted), but that won't work if the control is large/off the screen, so instead of CopyFromScreen maybe try using the PrintWindow API since it can capture windows behind other windows and off to the side of the desktop area....

Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
    Dim b As Bitmap = Capture_Window(Panel1)
    b.Save("M:\Cap_window.png", Imaging.ImageFormat.Png) ' save to png type file
    PictureBox1.Image = b
End Sub

Private Declare Function PrintWindow Lib "user32" (ByVal hwnd As IntPtr, ByVal hDC As IntPtr, ByVal nFlags As UInteger) As Boolean
Public Function Capture_Window(ByVal control As Control) As Bitmap
    Dim bmp As New Bitmap(control.Width, control.Height)
    Using g As Graphics = Graphics.FromImage(bmp)
        Dim hDC As IntPtr = g.GetHdc()
        PrintWindow(control.Handle, hDC, 0)
        g.ReleaseHdc(hDC)
    End Using
    Return bmp
End Function

EDIT: That won't work, where panel is larger then form it will be black, you'd have to set the panel as child of the desktop then capture it, what a hassle! Sorry!

[OmariCelestine]

Never did it but some ideas,
Draw every control using DrawToBitmap to a bitmap, but then you'd still have the same problem with the RichTextBox control.

Or use CopyFromScreen like above but temporarily resize the scrollable control so everything inside it is viewable (painted), but that won't work if the control is large/off the screen, so instead of CopyFromScreen maybe try using the PrintWindow API since it can capture windows behind other windows and off to the side of the desktop area....

Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
    Dim b As Bitmap = Capture_Window(Panel1)
    b.Save("M:\Cap_window.png", Imaging.ImageFormat.Png) ' save to png type file
    PictureBox1.Image = b
End Sub

Private Declare Function PrintWindow Lib "user32" (ByVal hwnd As IntPtr, ByVal hDC As IntPtr, ByVal nFlags As UInteger) As Boolean
Public Function Capture_Window(ByVal control As Control) As Bitmap
    Dim bmp As New Bitmap(control.Width, control.Height)
    Using g As Graphics = Graphics.FromImage(bmp)
        Dim hDC As IntPtr = g.GetHdc()
        PrintWindow(control.Handle, hDC, 0)
        g.ReleaseHdc(hDC)
    End Using
    Return bmp
End Function

EDIT: That won't work, where panel is larger then form it will be black, you'd have to set the panel as child of the desktop then capture it, what a hassle! Sorry!

In this case, it captures the panel with the scrollbars but does not print under the scrollable areas.

[OmariCelestine]

I got the issue resolved by combining a function I found elsewhere on the internet with the one I was using. Finally! Thank you all for your support.