Title | Print a form's image in VB.NET |
Description | This example shows how to print a form's image in VB.NET. It makes a Bitmap, uses BitBlt to copy the form's image into it, and prints the result. |
Keywords | print screen, screen capture, form image, print form image |
Categories | Graphics, VB.NET |
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Private Declare Auto Function BitBlt Lib "gdi32.dll" (ByVal _
hdcDest As IntPtr, ByVal nXDest As Integer, ByVal _
nYDest As Integer, ByVal nWidth As Integer, ByVal _
nHeight As Integer, ByVal hdcSrc As IntPtr, ByVal nXSrc _
As Integer, ByVal nYSrc As Integer, ByVal dwRop As _
System.Int32) As Boolean
Private Const SRCCOPY As Integer = &HCC0020
' Variables used to print.
Private m_PrintBitmap As Bitmap
Private WithEvents m_PrintDocument As PrintDocument
' Print the picture.
Private Sub btnPrint_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnPrint.Click
' Copy the form's image into a bitmap.
m_PrintBitmap = GetFormImage()
' Make a PrintDocument and print.
m_PrintDocument = New PrintDocument
m_PrintDocument.Print()
End Sub
Private Function GetFormImage() As Bitmap
' Get this form's Graphics object.
Dim me_gr As Graphics = Me.CreateGraphics
' Make a Bitmap to hold the image.
Dim bm As New Bitmap(Me.ClientSize.Width, _
Me.ClientSize.Height, me_gr)
Dim bm_gr As Graphics = me_gr.FromImage(bm)
Dim bm_hdc As IntPtr = bm_gr.GetHdc
' Get the form's hDC. We must do this after
' creating the new Bitmap, which uses me_gr.
Dim me_hdc As IntPtr = me_gr.GetHdc
' BitBlt the form's image onto the Bitmap.
BitBlt(bm_hdc, 0, 0, Me.ClientSize.Width, _
Me.ClientSize.Height, _
me_hdc, 0, 0, SRCCOPY)
me_gr.ReleaseHdc(me_hdc)
bm_gr.ReleaseHdc(bm_hdc)
' Return the result.
Return bm
End Function
' Print the form image.
Private Sub m_PrintDocument_PrintPage(ByVal sender As _
Object, ByVal e As _
System.Drawing.Printing.PrintPageEventArgs) Handles _
m_PrintDocument.PrintPage
' Draw the image centered.
Dim x As Integer = e.MarginBounds.X + _
(e.MarginBounds.Width - m_PrintBitmap.Width) \ 2
Dim y As Integer = e.MarginBounds.Y + _
(e.MarginBounds.Height - m_PrintBitmap.Height) \ 2
e.Graphics.DrawImage(m_PrintBitmap, x, y)
' There's only one page.
e.HasMorePages = False
End Sub
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