How To Print a Form That Is Too Large for the Screen or Page (230502)

MORE INFORMATION

If you need to print a form that is larger than the screen, or is only partially displayed, then the controls on the form must be placed in a PictureBox. This prints the bitmap that is contained in the PictureBox, instead of a screen capture of the form itself (which is what PrintForm does). Because the PictureBox's bitmap is stored in a device context in memory, you have access to the entire bitmap regardless of what is displayed.

NOTE: For the purposes of this article, the height of the form is set to 11 inches. If another paper size is desired, such as 8.5- X 14- inches, set the sTall variable to an appropriate value, for example, 14. Also note that these assignments are made in twips because this is the default scalemode for forms. If you change the scalemode, you need to change these values to match as well.

Print a Form That Is Larger Than the Screen

1. Start a new Standard EXE project in Visual Basic. Form1 is created by default.
2. Add two PictureBoxes to Form1.
   
   Avoid drawing the second PictureBox inside the first, because doing so makes the second PictureBox a member of the first. Instead, place the origin point of the second PictureBox to the left of the origin point of the first PictureBox.
3. Right-click Picture2 and choose Send to Back.
4. Add two labels to Picture1, leaving Picture2 empty.
5. Add the following code to the General Declarations section of Form1:

   Private Const twipFactor = 1440
   Private Const WM_PAINT = &HF
   Private Const WM_PRINT = &H317
   Private Const PRF_CLIENT = &H4&    ' Draw the window's client area.
   Private Const PRF_CHILDREN = &H10& ' Draw all visible child windows.
   Private Const PRF_OWNED = &H20&    ' Draw all owned windows.
   
   Private Declare Function SendMessage Lib "user32" Alias _
      "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, _
      ByVal wParam As Long, ByVal lParam As Long) As Long
      
   Private Sub Form_Load()
      Dim sWide As Single, sTall As Single
      Dim rv As Long
   
      Me.ScaleMode = vbTwips   ' default
      sWide = 8.5
      stall = 11   ' or 14, etc.
      Me.Width = twipFactor * sWide
      Me.Height = twipFactor * stall
      With Picture1
         .Top = 0
         .Left = 0
         .Width = twipFactor * sWide
         .Height = twipFactor * stall
      End With
      With Picture2
         .Top = 0
         .Left = 0
         .Width = twipFactor * sWide
         .Height = twipFactor * stall
      End With
      With Label1
         .Caption = "Top"
         .Left = Me.Width / 2
         .Top = 0
      End With
      With Label2
         .Caption = "Bottom"
         .Top = (twipFactor * stall) - .Height * 2
         .Left = Me.Width / 2
      End With
      Me.Visible = True
      DoEvents
   
      Picture1.SetFocus
      Picture2.AutoRedraw = True
      rv = SendMessage(Picture1.hwnd, WM_PAINT, Picture2.hDC, 0)
      rv = SendMessage(Picture1.hwnd, WM_PRINT, Picture2.hDC, _
      PRF_CHILDREN + PRF_CLIENT + PRF_OWNED)
      Picture2.Picture = Picture2.Image
      Picture2.AutoRedraw = False
   
      Printer.Print ""
      Printer.PaintPicture Picture2.Picture, 0, 0
      Printer.EndDoc
   End Sub
   					

6. Run the project.
7. The Top and Bottom labels should appear in their respective positions regardless of whether the form is completely displayed.

Print a Form on More Than One Page

If the form you are printing is too large to fit on a page, you can use the same approach as in the preceding example with a minor addition. The PaintPicture method has a number of optional parameters. The clipping region parameters can be used to grab a portion of the bitmap image and print it.

To accomplish this, locate the following code in the previous example:

Printer.Print ""
Printer.PaintPicture Picture2.Picture, 0, 0
Printer.EndDoc
				

Replace those three lines of code with the following:

Printer.Print ""
Printer.PaintPicture Picture2.Picture, 0, 0, , , _
   0, 0, , Picture2.Height / 2
Printer.NewPage
Printer.PaintPicture Picture2.Picture, 0, 0, , , _
   0, Picture2.Height / 2, , Picture2.Height / 2
Printer.EndDoc
				

For ease of illustration, this example merely divides the form in half. You can adjust the clipping region appropriately for your needs.

NOTE: Visual Basic 6.0 Online Help states that PrintForm prints the entire form, whether the entire form is visible or not. This information is incorrect.