Windows API Guide: IsWindow Function

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 LB_SETSEL to a multiple-selection list box selects or deselects one of its items. Alternatively, the message can select or deselect all of the items simultaneously. For a single-selection list box, sned the LB_SETCURSEL message instead.

Return Value

If successful, the message returns zero. If an error occured, the message returns LB_ERR.

Visual Basic-Specific Issues

None.

Parameters

wParam: If this is zero, the item is deselected. If this is a non-zero value, the item is selected.
lParam: The zero-based index of the item to select or deselect. If this is -1, all items in the list box are selected or deselected.

Constant Definitions

Const LB_SETSEL = &H185 Const LB_ERR = -1

Example

Change the selection in list box List1 so that the only selected items are the first and third items. To use this example, place a multiple-selection list box named List1 and a command button named Command1 on a form window.

' 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 LB_SETSEL = &H185 ' *** Place the following code inside the form window. *** Private Sub Command1_Click() Dim retval As Long  ' return value ' First, deselect all items in the list box. retval = SendMessage(List1.hWnd, LB_SETSEL, ByVal CLng(0), ByVal CLng(-1)) ' Then, select the first and third items. retval = SendMessage(List1.hWnd, LB_SETSEL, ByVal CLng(1), ByVal CLng(0)) retval = SendMessage(List1.hWnd, LB_SETSEL, ByVal CLng(1), ByVal CLng(2)) End Sub