WM_VSCROLL not picking up scroll wheel?

[i00]

I am overriding the WndProc to capture the WM_VSCROLL of a textbox / RTB... However this does not seem to capture the scroll event if it happens from a scroll wheel of a mouse ... how can i pick this up?... i can't use the MouseWheel event because this occurs when the mouse is scroll wheel is actually turned and not after the content is actually scrolled.

Thanks in advance,
Kris

[Edgemeal]

Like this...?

Private Const WM_MOUSEWHEEL As Int32 = &H20A

' Protected Overrides Sub...
If m.Msg = WM_MOUSEWHEEL Then
    If (m.WParam.ToInt32) / 65536 > 0 Then ' wheel direction upward
       
    Else ' wheel direction downward
        
    End If
End If

[i00]

Like this...?

Private Const WM_MOUSEWHEEL As Int32 = &H20A

' Protected Overrides Sub...
If m.Msg = WM_MOUSEWHEEL Then
    If (m.WParam.ToInt32) / 65536 > 0 Then ' wheel direction upward
       
    Else ' wheel direction downward
        
    End If
End If

Can't use WM_MOUSEWHEEL either because this ALSO occurs when the mouse is scroll wheel is actually turned and not after the content is actually scrolled.

Kris

[Edgemeal]

Can't use WM_MOUSEWHEEL either because this ALSO occurs when the mouse is scroll wheel is actually turned and not after the content is actually scrolled.

Kris

OK, I only tried it using a form and just called MyBase.WndProc(m) before checking WM_MOUSEWHEEL...

Public Class Form1

    Private Const WM_MOUSEWHEEL As Int32 = &H20A

    Private Sub Form1_MouseWheel(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel
        Debug.WriteLine("Form Wheel = " & e.Delta)
    End Sub

    Protected Overrides Sub WndProc(ByRef m As Message)
	Dim delta As Integer
        MyBase.WndProc(m)
        If m.Msg = WM_MOUSEWHEEL Then
            delta = m.WParam.ToInt32 \ 65536
            Debug.WriteLine("WndProc Wheel =  " & delta)
        End If
    End Sub

End Class

[i00]

OK, I only tried it using a form and just called MyBase.WndProc(m) before checking WM_MOUSEWHEEL...

Public Class Form1

    Private Const WM_MOUSEWHEEL As Int32 = &H20A

    Private Sub Form1_MouseWheel(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel
        Debug.WriteLine("Form Wheel = " & e.Delta)
    End Sub

    Protected Overrides Sub WndProc(ByRef m As Message)
	Dim delta As Integer
        MyBase.WndProc(m)
        If m.Msg = WM_MOUSEWHEEL Then
            delta = m.WParam.ToInt32 \ 65536
            Debug.WriteLine("WndProc Wheel =  " & delta)
        End If
    End Sub

End Class

Did that before you posted ... still doesn't work... i think it may have something to do with the smooth scrolling animations?... either way i need this to work...

Thanks
Kris

[i00]

Did that before you posted ... still doesn't work... i think it may have something to do with the smooth scrolling animations?... either way i need this to work...

Thanks
Kris

JUST REALISED THAT THIS WORKS FOR A TEXTBOX ... I NEED SOMETHING THAT WORKS FOR A RICHTEXTBOX also (as stated in #1) so it looks like i will need a specific case for this... any other ideas???

Thanks
Kris

[Edgemeal]

JUST REALISED THAT THIS WORKS FOR A TEXTBOX ... I NEED SOMETHING THAT WORKS FOR A RICHTEXTBOX also (as stated in #1) so it looks like i will need a specific case for this... any other ideas???

Thanks
Kris

I'm not sure how you detect if smooth scrolling is still in effect exactly, possible workarounds,
1) Override the wheel message and change it to a single line message so there is no smooth scrolling.

2) Haven't tried this but maybe save the scrollbar position, and after processed start a timer and check the position to see if is still changing...

Public Class RTB
    inherits richtextbox

    Protected Overrides Sub WndProc(ByRef m As Message)

        If m.Msg = WM_MOUSEWHEEL Or m.Msg = WM_VSCROLL Then
           ' save vert scrollbar position            
           lastVertPos = GetScrollPos(RTB.Handle, SB_VERT) 
        End If

        MyBase.WndProc(m)

        If m.Msg = WM_MOUSEWHEEL Or m.Msg = WM_VSCROLL Then
	    timer1.interval = 100ms
	    timer1.start
        End If
    End Sub

 sub timer1.tick(...)
    if  lastVertPos = GetScrollPos(RTB.Handle, SB_VERT)  then
      timer1.stop
   else
      'RTB still scrolling..., save pos.
      lastVertPos = GetScrollPos(RTB.Handle, SB_VERT) 
   end if
 end sub

End Class

EDIT Detect RichTextBox Smooth Scroll

Imports System.Runtime.InteropServices

Public Class Form1

    Private Structure POINT
        Public x As Integer
        Public y As Integer
    End Structure

    Private Const WM_USER As Integer = &H400
    Private Const EM_GETSCROLLPOS As Integer = WM_USER + 221
    Private Const EM_SETSCROLLPOS As Integer = WM_USER + 222

    <DllImport("user32.dll", EntryPoint:="SendMessage", ExactSpelling:=False, CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function SendMessage(hWnd As IntPtr, Msg As Integer, wParam As IntPtr, ByRef lParam As POINT) As Integer
    End Function

    Private scrollPos As New POINT

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Timer1.Interval = 50
    End Sub

    Private Sub RichTextBox1_MouseWheel(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles RichTextBox1.MouseWheel
        SendMessage(RichTextBox1.Handle, EM_GETSCROLLPOS, IntPtr.Zero, scrollPos)
        Timer1.Start()
    End Sub

    Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
        Dim p As New POINT
        'get scrollbar pos.
        SendMessage(RichTextBox1.Handle, EM_GETSCROLLPOS, IntPtr.Zero, p)
        ' compare scroll pos.
        If scrollPos.y = p.y Then
            Timer1.Stop()
            Debug.WriteLine("scrolling stopped.")
        Else
            ' save scrollbar pos.
            scrollPos.y = p.y
            Debug.WriteLine("smooth scrolling.")
        End If
    End Sub

End Class

[i00]

Hrm ... wish there was a better way ...

Kris