如何取得组合有一个Table里的CheckBox事件的对象

 private void TableBind(string HouseID,string HurdleID,string AnimalID,string Earmark,String i,bool b)
    { 

            TableRow Row = new TableRow();
            this.Table1.Rows.Add(Row);

            TableCell Cell = new TableCell();
            Cell.Width = Unit.Pixel(80);
   Cell.CssClass = "checkbox_td";
            Row.Cells.Add(Cell);
            CheckBox Chk = new CheckBox();
            Chk.ID = "CheckAnimalID" + i;
            Chk.Checked = b;
            Cell.Controls.Add(Chk);
            Chk.AutoPostBack = true;
            Chk.CheckedChanged += new EventHandler(Chk_CheckedChanged);       

          TableCell Cell2 = new TableCell();
            Cell2.Width = Unit.Pixel(160);
            Row.Cells.Add(Cell2);
            Cell2.Visible = false;
            Label LblHurdleId = new Label();
            LblHurdleId.Text = HurdleID;
            Cell2.Controls.Add(LblHurdleId);

            TableCell Celln = new TableCell();
            Celln.Width = Unit.Pixel(220);
            Row.Cells.Add(Celln);
            TextBox AnimalNum = new TextBox();
            AnimalNum.Width = Unit.Pixel(100);
            AnimalNum.ID = "TxtChgNum" + i;
            AnimalNum.Text = "0";
            Celln.Controls.Add(AnimalNum); 

    }

 private void Chk_CheckedChanged(object sender, EventArgs e)
    {
        CheckBox Chk = sender as CheckBox;//这个方法可取到所点的CheckBox对象
        string strId = Chk.ID;
           }