private void CmbBoxClient_DropDown(object sender, EventArgs e)
{
BLClient bLClient = new BLClient();
BindingList <ClientModel> lista = new BindingList <ClientModel>();
lista = bLClient.ClientList();
var source = new BindingSource(lista, null);
cmbBoxClient.ValueMember = "ClientId";
cmbBoxClient.DisplayMember = "Fullname";
cmbBoxClient.DataSource = source;
}