CB_RESETCONTENT 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_RESETCONTENT message to a combo box removes all the items from its drop-down box and edit control.

Return Value

This message always returns zero.

Visual Basic-Specific Issues

None.

Parameters

wParam: Not used -- set to 0.
lParam: Not used -- set to 0.

Constant Definitions

Const CB_RESETCONTENT = &H14B

Example

When the user clicks button Command1, empty the drop-down box of combo box Combo1, and then add three strings to it. The order in which the strings appear will depend on whether the combo box is sorted or not.

To use this example, place a combo box named Combo1 and a command button named Command1 on a form window. To verify that the combo box's list is being emptied, you may wish to add some items to it before running the 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_ADDSTRING = &H143
Public Const CB_RESETCONTENT = &H14B

' *** Place the following code inside a form window. ***

Private Sub Command1_Click()
	Dim retval As Long  ' return value
	
	' Empty the drop-down box of Combo1.
	retval = SendMessage(Combo1.hWnd, CB_RESETCONTENT, ByVal CLng(0), ByVal CLng(0))
	
	' Now add three strings to Combo1.  Their exact placement will
	' depend on whether Combo1 is sorted or not.
	retval = SendMessage(Combo1.hWnd, CB_ADDSTRING, ByVal CLng(0), ByVal "First Item Added")
	retval = SendMessage(Combo1.hWnd, CB_ADDSTRING, ByVal CLng(0), ByVal "Second Item Added")
	retval = SendMessage(Combo1.hWnd, CB_ADDSTRING, ByVal CLng(0), ByVal "Last Item Added")
End Sub