private void cboLoading_SelectedIndexChanged(object sender, EventArgs e) { if (cboLoading.SelectedIndex == -1) { return; } ncc.Search = cboLoading.Text; cboSearch.Items.Clear(); List <NhaCungCap> ncclist = nccbll.LocDanhSachNhaCungCap(ncc); if (cboLoading.Text == "Mã Cung Cấp") { cboSearch.Text = ""; foreach (NhaCungCap nccs in ncclist) { cboSearch.Items.Add(nccs.MaCC); } } else if (cboLoading.Text == "Tên Cung Cấp") { cboSearch.Text = ""; foreach (NhaCungCap nccs in ncclist) { cboSearch.Items.Add(nccs.TenCC); } } else if (cboLoading.Text == "Số Điện Thoại") { cboSearch.Text = ""; foreach (NhaCungCap nccs in ncclist) { cboSearch.Items.Add(nccs.Sdt); } } else { return; } }