How To Create an Incremental Search ComboBox

MORE INFORMATION

Step by Step Example

1. Start a new project in Visual Basic. Form1 is created by default.
2. Place a ComboBox control on the form.
3. Add the following code to the Form1 code window:

   Option Explicit
   
      Private Const WM_SETREDRAW = &HB
      Private Const KEY_A = 65
      Private Const KEY_Z = 90
      #If Win32 Then
   
      Private Declare Function SendMessage Lib "user32" Alias _
          "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, _
          ByVal wParam As Long, lParam As Long) As Long
   
      #Else
   
      Private Declare Function SendMessage Lib "User" ( _
          ByVal hwnd As Integer, ByVal wMsg As Integer, _
          ByVal wParam As Integer, lParam As Any) As Long
   
      #End If
      Private Sub Combo1_KeyUp(KeyCode As Integer, Shift As Integer)
        Dim sComboText As String
        Dim iLoop As Integer
        Dim sTempString As String
        Dim lReturn As Long
        If KeyCode >= KEY_A And KeyCode <= KEY_Z Then
          'only look at letters A-Z
          sTempString = Combo1.Text
          If Len(sTempString) = 1 Then sComboText = sTempString
          lReturn = SendMessage(Combo1.hWnd, WM_SETREDRAW, False, 0&)
          For iLoop = 0 To (Combo1.ListCount - 1)
            If UCase((sTempString & Mid$(Combo1.List(iLoop), _
              Len(sTempString) + 1))) = UCase(Combo1.List(iLoop)) Then
              Combo1.ListIndex = iLoop
              Combo1.Text = Combo1.List(iLoop)
              Combo1.SelStart = Len(sTempString)
              Combo1.SelLength = Len(Combo1.Text) - (Len(sTempString))
              sComboText = sComboText & Mid$(sTempString, Len(sComboText) + 1)
              Exit For
            Else
              If InStr(UCase(sTempString), UCase(sComboText)) Then
                sComboText = sComboText & Mid$(sTempString, Len(sComboText) _
                + 1)
                Combo1.Text = sComboText
                Combo1.SelStart = Len(Combo1.Text)
              Else
                sComboText = sTempString
                End If
            End If
          Next iLoop
          lReturn = SendMessage(Combo1.hWnd, _
          WM_SETREDRAW, True, 0&)
        End If
      End Sub
   
      Sub Form_load()
        Combo1.AddItem "Alpha"
        Combo1.AddItem "Beta"
        Combo1.AddItem "Charlie"
        Combo1.AddItem "Delta"
        Combo1.AddItem "Dingo"
      End Sub
   					

4. On the Run menu, click Start, or press the F5 key to run the program.