combobox: automatch item, select in other combobox, remove from both

10-07-2004, 02:06 PM

msmeth

Senior Contributor

Join Date: Sep 2003

Posts: 814

combobox: automatch item, select in other combobox, remove from both

I have 2 comboboxes and a listbox. I want the user to select an item from one combo, with then matches the item to its corresponding item in the 2nd combo, then add both to a list box. The user can either select from the 1st combo or from the 2nd...either one will match to the corresponding item in the other. Both comboboxes also have to be autocompleting. Once the selection is added to the listbox, the user can remove it which will delete the item from the list and add them back into the appropriate comboboxes. I have this working except for one thing.

When autocompleting, if the user types in what they want and its found and they hit ENTER, I am getting an error when trying to remove the item from the combos. It tells me the index is invalid and sure enough, when I check what the index is, its -1. It seems that the user isn't selecting an item in the combo even though its matched.

This is what I tried. It works if an item is clicked or chosen by pressing the up/down arrows. It also works if they type what they want, its matched, then they press up/down or some other number but will NOT work if they just type it, its found and they hit enter:

Code:

Private Sub cmdAdd_Click()
    List1.AddItem cmbo(0).Text & " " & cmbo(1).Text
    
    cmbo(0).RemoveItem (cmbo(0).ListIndex)
    cmbo(1).RemoveItem (cmbo(1).ListIndex)
    
End Sub

Oddly, if I put the opposite combo item to be deleted, it works...so, if I just selected something from combo 1, the following works:

Code:

Private Sub cmdAdd_Click()
    List1.AddItem cmbo(0).Text & " " & cmbo(1).Text
    
    cmbo(0).RemoveItem (cmbo(1).ListIndex)
    cmbo(1).RemoveItem (cmbo(1).ListIndex)
    
End Sub

Any ideas anyone? Perhaps I need to post the function I use for autocompleting? Let me know please...

10-07-2004, 02:21 PM

stevo

Senior Contributor

* Expert *

Join Date: May 2004

Location: Manchester, England.

Posts: 1,254

i think it would be best if we could see the function.

10-08-2004, 06:45 AM

msmeth

Senior Contributor

Join Date: Sep 2003

Posts: 814

Quote:

Originally Posted by stevo

i think it would be best if we could see the function.

I got it off a thread here and changed it a bit for my needs:

Code:

Option Explicit

'
'Implement CComboBox:SelectString to search and select item
'Y. Huang <yinghsuan_h@yahoo.com>
'
'Copyright? Naaa! But Copyleft...
'http://www.gnu.org/copyleft/copyleft.html
'
'In KeyPress Event Method: KeyAscii = AutoMatchCBBox(ComBoBox, KeyAscii)
'
'Reference: WinUser.h
'VB ComboBox doesn't have SelectString(), so SendMessage to the Window Handle
'#define CB_SELECTSTRING     0x014D
'#define CB_SHOWDROPDOWN     0x014F
'#define CBN_SELENDOK        9

Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
                ByVal hwnd As Long, _
                ByVal wMsg As Long, _
                ByVal wParam As Long, _
                lParam As Any) As Long
Private Const CB_ERR = -1, CB_SELECTSTRING = &H14D, CB_SHOWDROPDOWN = &H14F, CBN_SELENDOK = 9

'call this function in KeyPress event method
Public Function AutoMatchCBBox(ByRef cbBox As ComboBox, ByVal KeyAscii As Integer, CmbFollow As ComboBox) As Integer
    
    Dim strFindThis As String, bContinueSearch As Boolean
    Dim lResult As Long, lStart As Long, lLength As Long
    AutoMatchCBBox = 0 ' block cbBox since we handle everything
    bContinueSearch = True
    lStart = cbBox.SelStart
    lLength = cbBox.SelLength

    On Error GoTo ErrHandle
        
    If KeyAscii < 32 Then 'control char
        bContinueSearch = False
        cbBox.SelLength = 0 'select nothing since we will delete/enter
        If KeyAscii = Asc(vbBack) Then 'take care BackSpace and Delete first
            If lLength = 0 Then 'delete last char
                If Len(cbBox) > 0 Then ' in case user delete empty cbBox
                    cbBox.Text = Left(cbBox.Text, Len(cbBox) - 1)
                End If
            Else 'leave unselected char(s) and delete rest of text
                cbBox.Text = Left(cbBox.Text, lStart)
            End If
            cbBox.SelStart = Len(cbBox) 'set insertion position @ the end of string
        ElseIf KeyAscii = vbKeyReturn Then  'user select this string
          ' MsgBox cbBox.ListIndex <- when this is active, it returns -1
            cbBox.SelStart = Len(cbBox)
            lResult = SendMessage(cbBox.hwnd, CBN_SELENDOK, 0, 0)
            
            AutoMatchCBBox = KeyAscii 'give caller a chance to handle "Enter"
        End If
    Else 'generate searching string
        If lLength = 0 Then
            strFindThis = cbBox.Text & Chr(KeyAscii) 'No selection, append it
        Else
            strFindThis = Left(cbBox.Text, lStart) & Chr(KeyAscii)
        End If
    End If
    
    If bContinueSearch Then 'need to search
        Call VBComBoBoxDroppedDown(cbBox)  'open dropdown list
        lResult = SendMessage(cbBox.hwnd, CB_SELECTSTRING, -1, ByVal strFindThis)
        If lResult = CB_ERR Then 'not found
            cbBox.Text = strFindThis 'set cbBox as whatever it is
            cbBox.SelLength = 0 'no selected char(s) since not found
            cbBox.SelStart = Len(cbBox) 'set insertion position @ the end of string
        Else
            'found string, highlight rest of string for user
            cbBox.SelStart = Len(strFindThis)
            cbBox.SelLength = Len(cbBox) - cbBox.SelStart
            CmbFollow.ListIndex = cbBox.ListIndex
            
        End If
    End If
    On Error GoTo 0
    Exit Function
    
ErrHandle:
    'got problem, simply return whatever pass in
    Debug.Print "Failed: AutoCompleteComboBox due to : " & Err.Description
    Debug.Assert False
    AutoMatchCBBox = KeyAscii
    On Error GoTo 0
End Function

Last edited by msmeth; 10-08-2004 at 07:21 AM.