private void LoadComboBoxNewTenant() { TenantDA tenantDA = new TenantDA(); if (ComboBoxCurrentTenant.Items.Count > 0) { Tenant tenant = (Tenant)ComboBoxCurrentTenant.SelectedItem; ComboBoxNewTenant.DataSource = tenantDA.GetAllTenantsExcept(tenant.TenantID); } else { ComboBoxNewTenant.DataSource = tenantDA.GetAllTenants(); } ComboBoxNewTenant.DisplayMember = "Fullname"; ComboBoxNewTenant.ValueMember = "TenantID"; }