I set the datasource of multicolumncombobox everytime dropdown opening event is fired.
But on the first instance, it only show the header and a vertical scroll like 1st.png attachment. It did have rows since if I press downbutton, a row will be selected
while on the second instance and later, it works like 2nd.png attachment.
private void combobox_DropDownOpening(object sender, System.ComponentModel.CancelEventArgs args)
combobox.DataSource = datatable;