public void City() { try { int a = 0; if (cmbQY.Text != string.Empty) { if (cmbQY.Text != "中国") { a = Convert.ToInt32(cmbQY.SelectedValue); } } List <Model_Region> regionlist = new List <Model_Region>(); ResultModelOfArrayOfModel_Regiond4FqxSXX cit = cs.GetCity(a, true); if (cit.Code != 0) { MessageBox.Show(cit.Message); } else { foreach (Model_Region item in cit.Data) { Model_Region region = new Model_Region(); region.Idk__BackingField = item.Idk__BackingField; region.Namek__BackingField = item.Namek__BackingField; regionlist.Add(region); } } cmbCity.DisplayMember = "Namek__BackingField"; cmbCity.ValueMember = "Idk__BackingField"; cmbCity.DataSource = regionlist; } catch (Exception ex) { MessageBox.Show(ex.Message, "error", MessageBoxButtons.OK, MessageBoxIcon.Error); } }