根据列值填充数据网格视图中的下拉列表

Question

我想根据主要活动ID列填充Windows窗体中DataGridView的下拉列。

我有main activity id以及从存储过程返回的DataGridView中的其他详细信息。因此，当用户单击子活动列时，我需要根据此父ID填充子活动，然后根据此子活动，我需要填充其他下拉列。

╔══════════════╦══════════════════╦══════════╗
║ ActivityId   ║ ActivityName     ║ ParentId ║
╠══════════════╬══════════════════╬══════════╣
║ 10611801     ║ FootPath         ║ 106118   ║
║ 10611802     ║ Staggared Drains ║ 106118   ║
║ 10611901     ║ Manual Weeding   ║ 106119   ║
║ 10611902     ║ Chemical Weeding ║ 106119   ║
╚══════════════╩══════════════════╩══════════╝

我试图在DataGridView.CellClick事件中填充列，但我得到了

  

无效值异常

关于不同的主动性。

public partial class CustomDropDown : Form
{
    public CustomDropDown()
    {
        InitializeComponent();
    }


    public void BindGridData()
    {
        string selectQuery = "Select ActivityId as MainActivityId,ActivityName as MainActivity from ACTIVITY_MASTER_MST where ParentId is null";
        var mainDataSource = Common.GetDatas(selectQuery);
        dataGridView1.DataSource = mainDataSource;
        string sourceQuery = "Select convert(varchar,ActivityId) as SubActivityId,ActivityName as SubActivityName from ACTIVITY_MASTER_MST";
        var subActivityDataSource =Common.GetDatas(sourceQuery);
        PopulateGridDropDown(SubActivityId, subActivityDataSource, "SubActivityName", "SubActivityId");

    }
    public void PopulateGridDropDown(DataGridViewComboBoxColumn cbo, DataTable source, string displayMember, string valueMember)
    {
        cbo.DataSource = source;
        cbo.DisplayMember = displayMember;
        cbo.ValueMember = valueMember;
    }

    private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
    {
        var index = dataGridView1.CurrentCell.ColumnIndex;
        var rowIndex = dataGridView1.CurrentCell.RowIndex;
        string columnName = this.dataGridView1.Columns[index].Name;
        switch (columnName)
        {
            case "SubActivityId":

                var parentId = dataGridView1[MainActivityId.Name, rowIndex].Value;
                var strQuery = "Select convert(varchar,ActivityId) as SubActivityId,ActivityName as SubActivityName from ACTIVITY_MASTER_MST where ParentId=" + Convert.ToInt32( parentId);
                DataTable source = new DataTable();
                source = Common.GetDatas(strQuery);
                PopulateGridDropDown(SubActivityId, source, "SubActivityName", "SubActivityId");
              break;
            default:
                break;
        }
    }

    private void CustomDropDown_Load(object sender, EventArgs e)
    {
        BindGridData();
    }


}

请分享您的想法？