HOWTO: Scroll a Form When VB Forms Are Limited to Screen Size

• Microsoft Visual Basic Professional and Enterprise Editions, 16-bit only, for Windows, version 4.0
• Microsoft Visual Basic Standard and Professional Editions for Windows, version 3.0

SUMMARY

A Visual Basic form cannot be sized larger than the screen. This article explains how to scroll the contents of a form to enlarge the usable area of a form.

The sample program below works by scrolling a picture box control which is larger than the form and contains attached controls. When the picture box scrolls, all the attached controls scroll together.

MORE INFORMATION

Step-by-Step Example

1. Start a new project in Visual Basic. Form1 is created by default.



2. Add a horizontal scroll bar control and a vertical scroll bar control to Form1. (The size doesn't matter because the program automatically sizes the scroll bars in the Form Resize event code.)



3. Add a picture box control to Form1. Draw a text box control inside the upper-left corner of the picture box such that when the picture box moves, the text box moves with it.
   
   Select the Text1 box and press the F4 key to display the Properties window. Set the Text1 Index property to 0, which is required at design time to make an array of text controls.
   
   You can also enhance this sample program by placing more controls into the picture box. When the picture box scrolls, all the controls scroll.



4. Add the following code to the Form Load event:




      Sub Form_Load ()
         ' Make the picture box bigger than the form:
         Picture1.Move 0, 0, 1.4 * ScaleWidth, 1.2 * ScaleHeight ' Place
            some sample controls in the picture box:
         Dim i As Integer
         For i = 1 To 20
            Load Text1(i)
            Text1(i).Visible = True
            Text1(i).Left = i * Picture1.Height / 20
            Text1(i).Top = Text1(i).Left
         Next
      End Sub
 

5. Add the following code to the Form Resize event:




      Sub Form_Resize ()
         ' Position the scroll bars:
         hscroll1.Left = 0
         vscroll1.Top = 0
         If Picture1.Width > scalewidth Then
            hscroll1.Top = ScaleHeight - hscroll1.Height
         Else
            hscroll1.Top = ScaleHeight
         End If
         If Picture1.Height > hscroll1.Top Then
            vscroll1.Left = scalewidth - vscroll1.Width
            If Picture1.Width > vscroll1.Left Then
               hscroll1.Top = ScaleHeight - hscroll1.Height
            End If
         Else
            vscroll1.Left = scalewidth
         End If
         hscroll1.Width = scalewidth
         If hscroll1.Top > 0 then vscroll1.Height=hscroll1.Top
         ' Set the scroll bar ranges
         hscroll1.Max = Picture1.Width - vscroll1.Left
         vscroll1.Max = Picture1.Height - hscroll1.Top
         hscroll1.SmallChange = Abs(hscroll1.Max \ 16) + 1
         hscroll1.LargeChange = Abs(hscroll1.Max \ 4) + 1
         vscroll1.SmallChange = Abs(vscroll1.Max \ 16) + 1
         vscroll1.LargeChange = Abs(vscroll1.Max \ 4) + 1
         hscroll1.ZOrder 0
         vscroll1.ZOrder 0
      End Sub
 

6. Add the following code to the HScroll1 Change event:




      Sub HScroll1_Change ()
         Picture1.Left = -HScroll1.Value
      End Sub 

7. Add the following code to the VScroll1 Change event:




      Sub VScroll1_Change ()
         Picture1.Top = -VScroll1.Value
      End Sub 

8. Start the program (or press the F5 key). Click the scroll bars to scroll the form. Close the form to end the program.

Additional query words: 3.00 4.00 vb416

Keywords          : kb16bitonly kbVBp300 kbVBp400 PrgOther 
Version           : WINDOWS:3.0,4.0
Platform          : WINDOWS 
Issue type        : kbhowto 

Last Reviewed: July 20, 1999