RichTextBox Visible ScrollBars check 1

[robdon]

Hi,

Does anyone know how to detect if a RichTextBox has the Vertical Scroll Bar visible.

Not the RichTextBox.ScrollBars property.

But if RichTextBox.ScrollBars = rtfBoth, I need to actually know if the scroll bar is visible at a certain time.

Because if the RichTextBox does not have many lines in it, then the scrollbar is not visible, and I need to know if the scroll bar is there or not.

Thanks,

Rob D

 

[BobRodes]

This should work:

Option Explicit

Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long

Private Const EM_GETLINECOUNT = &HBA

Private Sub RichTextBox1_Change()
Dim LineCt As Long
LineCt = SendMessage(RichTextBox1.hwnd, EM_GETLINECOUNT, 0&, 0&)
End Sub

Once you have the line count, it's just a matter of knowing how many lines before you have a scroll bar. How to do this depends on things like whether you dynamically resize the control and so on.

HTH

Bob

 

[BobRodes]

This won't be entirely reliable if you have multiple font sizes supported, though. Maybe someone else can improve this.

 

[robdon]

Hi,

My rich text box is dynamically sized, so it can change.

Any other ideas, anyone?

Thanks,

Rob D.

 

[Hypetia]

You can check the presence of a scroll bar by checking the corresponding bit in window style. A window contains WS_VSCROLL and WS_HSCROLL style bits to indicate the presence of vertical and horizontal scroll bar respectively.
___
[tt]
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Const GWL_STYLE = -16
Private Const WS_HSCROLL = &H100000
Private Const WS_VSCROLL = &H200000
...
Dim dwStyle As Long
dwStyle = GetWindowLong(RichTextBox1.hwnd, GWL_STYLE)
If (dwStyle And WS_VSCROLL) Then Debug.Print "Has Vertical SB"
If (dwStyle And WS_HSCROLL) Then Debug.Print "Has Horizontal SB"[/tt]

 

[robdon]

Hi Hypetia,

That was just what I was looking for.

Thanks for the help,

Rob D.

 

[BobRodes]

There you go! I felt pretty sure there was something like that somewhere.