DataGridViewComboBox值无效

Question

我用以下代码填充我的datagridview code列：

 (dgvHopDong.Columns["MaNCC"] as DataGridViewComboBoxColumn).DataSource = QL.NhaCungCaps.Select(n => new { MaNCC = n.MaNCC, TenNCC = n.TenNCC }).ToList();            
            (dgvHopDong.Columns["MaNCC"] as DataGridViewComboBoxColumn).DisplayMember = "TenNCC";
            (dgvHopDong.Columns["MaNCC"] as DataGridViewComboBoxColumn).ValueMember = "MaNCC";

错误是：

DataGridViewComboBoxCell值无效吗？

我不知道为什么。非常感谢!

Answer 1

缺少值类型。

(dgvHopDong.Columns["MaNCC"] as DataGridViewComboBoxColumn).ValueType = typeof(string);