How to dropdown a datacombo programmatically?

[shark]

How to dropdown a datacombo(not a common combobox) programmatically in Visual Basic?

[Iouri]

'
'Comments
'This code allows you To:
'Drop it down through code: DropDown(cbo As ComboBox, blnShow As Boolean)
'Set the drop down height: SetDropHeight(cbo As ComboBox, lngHeight As Long)
'Set the drop down Width: SetDropWidth(cbo As ComboBox, lngWidth As Long)
'
'
'Code

Option Explicit

'// Windows API calls
Private Declare Function SendMessageLong Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Function MoveWindow Lib "user32" (ByVal hwnd As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal bRepaint As Long) As Long
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hwndParent As Long, ByVal hwndChildAfter As Long, ByVal lpszClass As String, ByVal lpszWindow As String) As Long

'// Windows message
Private Const WM_USER = &H400

'// Combo and edit box messages
Private Const CB_SHOWDROPDOWN = WM_USER + 15
Private Const CB_SETDROPPEDWIDTH = &H160
Private Const EC_LEFTMARGIN = &H1
Private Const EC_RIGHTMARGIN = &H2
Private Const EC_USEFONTINFO = &HFFFF&
Private Const EM_SETMARGINS = &HD3&
Private Const EM_GETMARGINS = &HD4&

Public Sub SetDropWidth(cbo As ComboBox, lngWidth As Long)

SendMessageLong cbo.hwnd, CB_SETDROPPEDWIDTH, lngWidth, 0

End Sub

Public Sub SetDropHeight(cbo As ComboBox, lngHeight As Long)

Dim intScaleMode As Integer

'// Store the current scalemode
intScaleMode = cbo.Parent.ScaleMode
'// Set it to pixels
cbo.Parent.ScaleMode = vbPixels
'// Move the check box
MoveWindow cbo.hwnd, cbo.Left, cbo.Top, cbo.Width, lngHeight, 1
'// Reset the scalemode
cbo.Parent.ScaleMode = intScaleMode

End Sub


Public Sub DropDown(cbo As ComboBox, blnShow As Boolean)

If blnShow Then
SendMessageLong cbo.hwnd, CB_SHOWDROPDOWN, 1, ByVal 0&
Else
SendMessageLong cbo.hwnd, CB_SHOWDROPDOWN, 0, ByVal 0&
End If

End Sub



Iouri Boutchkine
iouri@hotsheet.com