Currently, The control supports only single selection. Use the SelectCount property to determine whether the control has an item selected. Use the CellCaption property to get the caption of a specified cell. Use the Value property to get the selected value on a single column control. If the control contains multiple columns you can use the Select property to get the selected value on a specified column. 

The following VB sample displays the selected item, using the SelectedItem property:

With ComboBox1.Items
    Dim h As HITEM
    h = .SelectedItem()
    If (Not h = 0) Then
       Debug.Print .CellCaption(h, 0)
    End If
End With

The following C++ sample displays the selected item, using the SelectedItem property:

CItems items = m_combobox.GetItems();
long hItem = items.GetSelectedItem( 0 );
if ( hItem != 0 )
	OutputDebugString( V2S( &items.GetCellCaption( COleVariant( hItem ), COleVariant( long(0) ) ) ) );

where the V2S function converts a VARIANT value to a string,

static CString V2S( VARIANT* pv, LPCTSTR szDefault = _T("") )
{
	if ( pv )
	{
		if ( pv->vt == VT_ERROR )
			return szDefault;

		COleVariant vt;
		vt.ChangeType( VT_BSTR, pv );
		return V_BSTR( &vt );
	}
	return szDefault;
} 

The following VB.NET sample displays the selected item, using the SelectedItem property:

With AxComboBox1.Items
    Dim h As Integer = .SelectedItem()
    If (Not h = 0) Then
        Debug.WriteLine(.CellCaption(h, 0))
    End If
End With

The following C# sample displays the selected item, using the SelectedItem property:

EXCOMBOBOXLib.Items items = axComboBox1.Items;
int hItem = items.get_SelectedItem(0);
if ( hItem != 0 )
	System.Diagnostics.Debug.WriteLine(items.get_CellCaption(hItem,0).ToString());

The following VFP sample displays the selected item, using the SelectedItem property:

With thisform.ComboBox1.Items
	.DefaultItem = .SelectedItem(0)
	If (.DefaultItem <> 0) Then
		wait window nowait .CellCaption(0, 0)
	EndIf
EndWith