This example shows how to make a combo box act like those found in Quickenor Microsoft Access, without using a third-party VBX. As each characteris typed, the elements in the combo box are searched and, if a match isfound, retrieved. If a match is not found, the original typed text is restored.The only code needed resides in the KeyUp event of a combo box called combo1.The combo box is sorted alphabetically, so it stops on the first alphabeticalmatch. I use the SendMessage API to turn the redraw of the combo box offand then on when the search is complete. Here are the form-level declarations for the combo box:
Dim strCombo As StringConst WM_SETREDRAW = &HBConst KEY_A = 65Const KEY_Z = 90Declare Function SendMessage Lib "User" _ (ByVal hWnd As Integer, _ ByVal wMsg As Integer, _ ByVal wParam As Integer, _ lParam As Any) As LongThe code in the KeyUp event looks like this:
Dim x%Dim strTemp$Dim nRet&If Keycode >= KEY_A And Keycode <= KEY_Z Then'only look at letters A-Z strTemp = combo1.Text If Len(strTemp) = 1 Then strCombo = strTemp nRet& = SendMessage(combo1.hWnd, _ WM_SETREDRAW, False, 0&) For x = 0 To (combo1.ListCount - 1) If UCase((strTemp & _ Mid$(combo1.List(x), _ Len(strTemp) + 1))) =UCase(combo1.List(x)) Then combo1.ListIndex = x combo1.Text = combo1.List(x) combo1.SelStart = Len(strTemp) combo1.SelLength = _ Len(combo1.Text) - (Len(strTemp)) strCombo = strCombo & _ Mid$(strTemp, Len(strCombo) + 1) Exit For Else If InStr(UCase(strTemp), _ UCase(strCombo)) Then strCombo = strCombo & _ Mid$(strTemp, Len(strCombo) + 1) combo1.Text = strCombo combo1.SelStart = Len(combo1.Text) Else strCombo = strTemp End If End IfNextnRet& = SendMessage(combo1.hWnd, _ WM_SETREDRAW, True, 0&)End If
