How To Detect If Scroll Bars Are Visible on a Control (299686)

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Step-by-Step Example

1. Start a new Standard EXE project in Visual Basic. Form1 is created by default.
2. On the Project menu, click Components. In the Components dialog box, select the Microsoft Windows Common Controls 6.0 check box, and then click OK.
3. Add one TreeView and two CommandButton controls to Form1.
4. Add the following code to the General Declarations section of Form1:

   Option Explicit
   
   Private Const GWL_STYLE = (-16)
   Private Const WS_HSCROLL = &H100000
   Private Const WS_VSCROLL = &H200000
   
   Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" & _
      (ByVal hwnd As Long, ByVal nIndex As Long) As Long
   
   Private Sub Command1_Click()
       Dim wndStyle As Long
       
       ' Retrieve the window style of the control.
       wndStyle = GetWindowLong(TreeView1.hwnd, GWL_STYLE)
   
       ' Test if the horizontal scroll bar style is present
       ' in the window style, indicating that a horizontal
       ' scroll bar is visible.
       If (wndStyle And WS_HSCROLL) <> 0 Then
           MsgBox "A horizontal scroll bar is visible."
       Else
           MsgBox "A horizontal scroll bar is NOT visible."
       End If
     
       ' Test if the vertical scroll bar style is present
       ' in the window style, indicating that a vertical
       ' scroll bar is visible.
       If (wndStyle And WS_VSCROLL) <> 0 Then
           MsgBox "A vertical scroll bar is visible."
       Else
           MsgBox "A vertical scroll bar is NOT visible."
       End If
   End Sub
   
   Private Sub Command2_Click()
       ' Make the size of the control smaller
       ' so that the scroll bars will appear.
       TreeView1.Move 250, 900, 1000, 1000
   End Sub
   
   Private Sub Form_Load()
       ' Size and position the form and controls.
       Form1.ScaleMode = 1
       Form1.Move 0, 0, 5100, 5040
       Command1.Caption = "Scroll Bar Test"
       Command1.Move 120, 120, 1700, 500
       Command2.Caption = "Size Control"
       Command2.Move 2000, 120, 1700, 500
       TreeView1.Move 250, 900, 3000, 1500
       
       ' Add sample text to the TreeView control.
       TreeView1.Nodes.Add , , , "1: Sample Text"
       TreeView1.Nodes.Add , , , "2: Sample Text"
       TreeView1.Nodes.Add , , , "3: Sample Text"
       TreeView1.Nodes.Add , , , "4: Sample Text"
   End Sub
   					

5. Run the project. Notice that no scroll bars are present on the TreeView control.
6. Click Scroll Bar Test. A message box indicates that a horizontal scroll bar is not present. Another message box indicates that a vertical scroll bar is not present.
7. Click Size Control. Notice that the height and width of the TreeView control are smaller and that both a horizontal and vertical scroll bar are visible.
8. Click Scroll Bar Test. A message box indicates that a horizontal scroll bar is present, which is followed by another message box that indicates that a vertical scroll bar is present.