[RESOLVED] Scrolling Combobox without mouse wheel

[Spajder]

Hi, i'm having a combobox with 12 items and I would like to scroll these items
with my mouse disabled (only with my keyboard).
Is there an example how to achieve this?

Thanks in advance for your answers.

[LaVolpe]

Set focus to the combobox and press the down/up arrows. Otherwise, how do you plan on scrolling? Let's say you use the Down/Up arrows and trap them before other controls get them (Form's KeyPreview property set to True). Now you can change the ListIndex of the combobox to "scroll". However, if you trap those keys, then other controls won't have them either, like a textbox, richtexboxt, and other scrollable controls. Can you give more details?

Welcome to the forums.

[Spajder]

Hi LaVolpe,

my Form's KeyPreview is set to true. I have no problems with my keys or my keyboard, the problem is my mouse and its wheel. With so many items, I have in my combobox a scrollbar, scrollable with mouse. My client wants, that mouse scrolling with its wheel is disabled and wants, that items in combobox are scrollable only with keyboard (up or down). It is a weird request and I have no idea, how to achieve this.

[LaVolpe]

For each up/down arrow action, simply change the ListIndex of the combobox.

' moving down in the list
If Combo1.ListIndex = Combo1.ListCount -1 Then ' on last list item
    Combo1.ListIndex = 0 ' move to first or don't move at all; your choice
Else
    Combo1.ListIndex = Combo1.ListIndex + 1
End If
' scrolling up; pretty much the reverse
If Combo1.ListIndex = 0 Then ' at the top of the list
    Combo1.ListIndex = Combo1.ListCount -1 ' move to bottom or don't move at all
Else
    Combo1.ListIndex = Combo1.ListIndex -1
End If

[Amr Al-Amir]

If you know subclassing this will be easy

a simple way for subclassing is the SmartSubclass Library, you can download it from this link SmartSubclass DLL

- create a new project with a combobox named combo1 and has any no of items

- extract the file "SmartSubClass.dll"

- reference it : Project --> references --> Browse --> select the file --> open --> ok

- in Form1 code module insert the following code:

Option Explicit

Dim WithEvents oSniff As SmartSubClassLib.SmartSubClass

Private Sub Form_Load()
  Set oSniff = New SmartSubClassLib.SmartSubClass
  oSniff.SubClassHwnd Combo1.hWnd, True
End Sub

Private Sub Form_Unload(Cancel As Integer)
  oSniff.SubClassHwnd Combo1.hWnd, False
End Sub

Private Sub oSniff_NewMessage(ByVal hWnd As Long, uMsg As Long, wParam As Long, lParam As Long, Cancel As Boolean)
  Select Case hWnd
    Case Combo1.hWnd
      Select Case uMsg
        Case &H20A&
          uMsg = 0
      End Select
  End Select
End Sub

[Spajder]

Amr Al-Amir, this is what I was searching for! Thank you very much for your reply

[Amr Al-Amir]

You are welcome

[bdevore]

If you know subclassing this will be easy

a simple way for subclassing is the SmartSubclass Library, you can download it from this link SmartSubclass DLL

- create a new project with a combobox named combo1 and has any no of items

- extract the file "SmartSubClass.dll"

- reference it : Project --> references --> Browse --> select the file --> open --> ok

- in Form1 code module insert the following code:

Option Explicit

Dim WithEvents oSniff As SmartSubClassLib.SmartSubClass

Private Sub Form_Load()
  Set oSniff = New SmartSubClassLib.SmartSubClass
  oSniff.SubClassHwnd Combo1.hWnd, True
End Sub

Private Sub Form_Unload(Cancel As Integer)
  oSniff.SubClassHwnd Combo1.hWnd, False
End Sub

Private Sub oSniff_NewMessage(ByVal hWnd As Long, uMsg As Long, wParam As Long, lParam As Long, Cancel As Boolean)
  Select Case hWnd
    Case Combo1.hWnd
      Select Case uMsg
        Case &H20A&
          uMsg = 0
      End Select
  End Select
End Sub

This works fine. If you have the time, I would like to know how to get my 'dropdown combo' to drop down. I've tried hacking in some code into your oSniff sub; but nothing I've tried works. I really need this functionality and would be very appreciative of your help.

Thanks,

Bob DeVore

[Spajder]

Hi Bob,

it should be enough, if the style of your Combobox is 0 - Dropdown Combo. You can set his style in the Properties Window.

[Amr Al-Amir]

No need for the oSniff things

create a new project with a combobox named combo1 and a command button Named command1, populate the combobox list (may be from the 'list' property) and into the form insert this code

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 CB_SHOWDROPDOWN = &H14F

Private Sub Command1_Click()
  SendMessage Combo1.hwnd, CB_SHOWDROPDOWN, True, 0
End Sub