DataGridView检查是否选中了复选框

Question

我在StackOverflow和整个互联网上浏览了很多但却找不到任何可以帮助我的东西。我将一些SQL数据库中的信息放到DataGridView上，我正在添加一个带复选框的额外列。

 private void populatedataGrid()
        {
            String sql = "SELECT pm.Name, pm.telephone, pm.email, pm.validID, comp.name as `Company` FROM `project managers`as pm JOIN `companies`as comp ON pm.Companies_companyID = comp.companyID where pm.Companies_companyID =" + loginID;
            MySqlCommand command = new MySqlCommand(sql, dh.Connection);

            try
            {
                MySqlDataAdapter adapter = new MySqlDataAdapter();
                adapter.SelectCommand = command;
                DataTable dbdataset = new DataTable();
                adapter.Fill(dbdataset);
                BindingSource bSource = new BindingSource();

                // DataGridView1 is a different DataGrid, i am working on DataGridView2
                bSource.DataSource = dbdataset;
                dataGridView1.DataSource = bSource;
                dataGridView2.DataSource = bSource;
                //Method for adding the additional column with checkboxes (ill paste the method below)
                addCheckBoxColumn();
                //I make it so that only the checkboxes can be edited
                foreach (DataGridViewColumn dc in dataGridView2.Columns)
                {
                    if (dc.Index.Equals(5))
                    {
                        dc.ReadOnly = false;
                    }
                    else
                    {
                        dc.ReadOnly = true;
                    }
                }
                adapter.Update(dbdataset);


            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                dh.Connection.Close();
            }

}

以下是使用Checkboxes创建列的方法：

 private void addCheckBoxColumn()
        {
            DataGridViewCheckBoxColumn cbCol = new DataGridViewCheckBoxColumn();
            cbCol.ValueType = typeof(bool);
            cbCol.Name = "Select";
            cbCol.HeaderText = "Select";
            dataGridView2.Columns.Add(cbCol);
        }

现在一切正常：

我创建了一个用于测试目的的按钮，我想在单击时在label2上写入要检查的复选框的名称。所以这就是我写的方法：

private void button1_Click(object sender, EventArgs e)
        {
            foreach (DataGridViewRow row in dataGridView2.Rows)
            {
                DataGridViewCheckBoxCell cbxcell = row.Cells[5] as DataGridViewCheckBoxCell;

                if ((bool)cbxcell.Value == true)
                {
                    label2.Text = row.Cells[1].Value.ToString();
                }
            }
        }

当我运行它并单击Button1时，我得到以下异常： “BuildID-Company-Backend.exe中发生了'System.NullReferenceException'类型的未处理异常

附加信息：对象引用未设置为对象的实例。“

有什么想法吗？ ：（