Unlike the TextBox control, the ComboBox control doesn’t expose any MaxLength property, so you have no means of limiting the numbers of characters typed by the end user in the edit area. However you can set this value by sending a CB_LIMITTEXT message to the control, passing the maximum number of characters in the wParam argument. The following code encapsulates this feature in a reausable routine:
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal _ hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _ lParam As Any) As LongConst CB_LIMITTEXT = &H141' Set the maximum number of characters that can be entered in a ComboBox controlSub SetComboMaxLength(ComboBox As ComboBox, ByVal lMaxLength As Long) SendMessageLong ComboBox.hWnd, CB_LIMITTEXT, lMaxLength, Byval 0&)End Sub
