Object不是DataGridView的对象实例

Question

我试图提供一个SQL列表，它将加载到datagridview中。之后，某些字段必须是DataGridViewComboBoxColumn类型，因此用户可以从组合框列中选择任何选项。这是我所做的代码：

public async void ConfigurarGrilla()
    {
        try
        {
            var responseArea = await servicio.AreaGetAllAsync();
            var responseEmpresa = await servicio.EmpresaGetAllAsync();

            if (responseArea.IsValid && responseEmpresa.IsValid)
            {
                listaArea = responseArea.Value;
                listaEmpresa = responseEmpresa.Value;

                dgvArticulos.AutoGenerateColumns = false;

                DataGridViewComboBoxColumn dtColumn = dgvArticulos.Columns["CodArea"] as DataGridViewComboBoxColumn;
                dtColumn.DataSource = listaArea;
                dtColumn.DisplayMember = "CodArea";

                DataGridViewComboBoxColumn dtColumn2 = (DataGridViewComboBoxColumn)dgvArticulos.Columns["RazonSocial"] as DataGridViewComboBoxColumn;
                dtColumn2.DataSource = listaEmpresa;
                dtColumn2.DisplayMember = "RazonSocial";

                LoadDocumento();
            }
            else
            {
                MessageBox.Show(responseArea.ErrorMensaje);
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show("Ocurrio un error " + ex.Message, "Aviso", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

responseArea.Value和responseEmpresa.Value方法从BD中获取列表，它们在我调试时包含信息，但是在行中dtColumn.DataSource = listaArea是我得到错误的地方

  

＆＃34;对象引用未设置为对象的实例＆＃34;

我不知道问题是什么。我的所有对象都已初始化