CB_SHOWDROPDOWN Message

Platforms

Windows 95: Supported.
Windows 98: Supported.
Windows NT: Requires Windows NT 3.1 or later.
Windows 2000: Supported.
Windows CE: Requires Windows CE 1.0 or later.

Description & Usage

Sending the CB_SHOWDROPDOWN message to a combo box opens or closes its drop-down list box section. Naturally, this message only works if the combo box has a list that can be dropped down, instead of always or never displaying it.

Return Value

This message always returns a non-zero value.

Visual Basic-Specific Issues

None.

Parameters

wParam: If zero, closes the drop-down list of the combo box. If non-zero, opens the drop-down list of the combo box.
lParam: Not used -- set to 0.

Constant Definitions

Const CB_SHOWDROPDOWN = &H14F

Example

' This code is licensed according to the terms and conditions listed here.

' Declarations and such needed for the example:
' (Copy them to the (declarations) section of a module.)
Public Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hWnd _
	As Long, ByVal Msg As Long, wParam As Any, lParam As Any) As Long
Public Const CB_SHOWDROPDOWN = &H14F

' Display the drop-down list box of combo box Combo1.
Dim retval As Long  ' return value

retval = SendMessage(Combo1.hWnd, CB_SHOWDROPDOWN, ByVal CLng(1), ByVal CLng(0))