How to get the new and old values when an item is selected in a combobox cell in WinForms GridControl?

//Hook the Event in Form_Load
this.gridControl1.CurrentCellCloseDropDown += gridControl1_CurrentCellCloseDropDown;  
void gridControl1_CurrentCellCloseDropDown(object sender, Syncfusion.Windows.Forms.PopupClosedEventArgs e)
{
    cc = this.gridControl1.CurrentCell;           
    // show the new value in the ComboBox selected item
    MessageBox.Show("New Value is " + cc.Renderer.GetCellValue().ToString());
    // Show the old value in the ComboBox selected item
    MessageBox.Show("Old Value is " + this.gridControl1[cc.RowIndex, cc.ColIndex].CellValue.ToString());
}

'Hook the Event in Form_Load
Me.gridControl1.CurrentCellCloseDropDown += gridControl1_CurrentCellCloseDropDown
Private Sub gridControl1_CurrentCellCloseDropDown(ByVal sender As Object, ByVal e As Syncfusion.Windows.Forms.PopupClosedEventArgs)
    cc = Me.gridControl1.CurrentCell
    ' show the new value in the ComboBox selected item
    MessageBox.Show("New Value is " & cc.Renderer.GetCellValue().ToString())
    ' Show the old value in the ComboBox selected item
    MessageBox.Show("Old Value is " & Me.gridControl1(cc.RowIndex, cc.ColIndex).CellValue.ToString())
End Sub