Forum

Hi,
I’ve got a problem with the new v2.70. If I call GetItemData() of a CExtComboBox I always get 0 returned.

DefWindowProc returns the correct value. In an older version there was
a IsPopupListSupported() call before.


new code:

LRESULT CExtComboBoxBase::OnCBGetItemData( WPARAM wParam, LPARAM lParam )
{
    ASSERT_VALID( this );
LRESULT lResult = DefWindowProc( CB_GETITEMDATA, wParam, lParam );
    if( lResult != CB_ERR )        
    {
        LB_ITEM * pItemDataExt = (LB_ITEM *) lResult;
        ASSERT( pItemDataExt != NULL );
        if(        pItemDataExt != NULL
            &&    AfxIsMemoryBlock(
                    static_cast < LPVOID > ( pItemDataExt ),
                    sizeof( LB_ITEM )
                    )
            )
            lResult = pItemDataExt->DataGet();
        else
            lResult = 0L;
    }
    return lResult;
}


old code:

LRESULT CExtComboBoxBase::OnCBGetItemData( WPARAM wParam, LPARAM lParam )
{
    ASSERT_VALID( this );
LRESULT lResult = DefWindowProc( CB_GETITEMDATA, wParam, lParam );
    if(        lResult != CB_ERR
        &&    IsPopupListSupported()
        )        
    {
        LB_ITEM * pItemDataExt = (LB_ITEM *) lResult;
        ASSERT( pItemDataExt != NULL );
        if(        pItemDataExt != NULL
            &&    ::AfxIsValidAddress(
                    static_cast < LPVOID > ( pItemDataExt ),
                    sizeof( LB_ITEM )
                    )
            )
            lResult = pItemDataExt->DataGet();
        else
            lResult = 0L;
    }
    return lResult;
}


Any idea?

Thanks for any help!

Best regards
Michael

There are many combo boxes in our samples and they all work OK. For example on the Buttons page in the Prof-UIS_Controls sample there is a Cursor combo box (IDC_CURSOR). During its initialization we assign user data to its items and then analyze it in the CPageButtons::OnSelendokCursor() method when THE selection changes. We would recommend you look at this sample and compare both combo boxes.