如何获取动态复选框控件 ID

我正在动态生成复选框，所有这些都是用page_load写的，当我尝试选中显示错误的复选框时，

错误行：

CheckBox cb = (CheckBox)Page.FindControl("chk" + j);

错误：找到具有相同 ID "1"的多个控件。FindControl 要求控件具有唯一的 ID

我的要求是：

如果我选中复选框，我希望计算选中

的复选框数量，单选按钮将相对选中复选框出现。

下面是代码：

      string strfromdt = Session["leavefrm"].ToString();
        DateTime startDate = Convert.ToDateTime(strfromdt);
        string strtodt = Session["leaveto"].ToString();
        DateTime endDate = Convert.ToDateTime(strtodt);
        string strdays = Session["noofdays"].ToString();
        float daysf = float.Parse(strdays);
        float days = (float)Math.Ceiling(daysf);
        CheckBox chk;
        Label lbl;
        RadioButton rd;
        days++;
                OleDbCommand cmd;
                DbConnection.Open();
                cmd = new OleDbCommand("select HOL_DATE from IND_HOLIDAYS", DbConnection);
                OleDbDataAdapter da = new OleDbDataAdapter(cmd);
                DataTable dt = new DataTable();
                da.Fill(dt);

                for (int j = 1; j <= days - 1; j++)
                {
                    while(startDate <= endDate)
                    {
                        for (int i = 0; i <= dt.Rows.Count - 1; i++)
                        {
                            string strdate = dt.Rows[i]["HOL_DATE"].ToString();
                            DateTime date = Convert.ToDateTime(strdate);
                            if (startDate == date)
                                startDate = startDate.AddDays(1);
                        }
                        if ((startDate.DayOfWeek == DayOfWeek.Saturday) || ((startDate.DayOfWeek == DayOfWeek.Sunday)))
                        {
                            startDate = startDate.AddDays(1);
                            continue;
                        }
                        break;
                    }

                    chk = new CheckBox();
                    chk.ID = j.ToString();
                    chk.AutoPostBack = true;
                    // chk.Checked = true;
                    lbl = new Label();
                    lbl.Text = startDate.ToString("dd/MM/yyyy");
                    lbl.ID = j.ToString();
                    PlaceHolder1.Controls.Add(lbl);
                    PlaceHolder1.Controls.Add(chk);
                    PlaceHolder1.Controls.Add(new RadioButton { });
                    PlaceHolder1.Controls.Add(new LiteralControl("<BR>"));
                    startDate = startDate.AddDays(1);

                    CheckBox cb = (CheckBox)Page.FindControl("chk" + j);
                   //chk.Checked = CheckBox1Checked;
                   //chk.oncheckedchanged += CheckBox1OnChecked;
                    int chkcount = 0;
                    if (chk.Checked)
                    {
                        chkcount++;
                    }
                    int chkcount1 = chkcount;
                }

chk.ID = string.Format("chk{0}", j);
lbl.ID = string.Format("lbl{0}", j);
// Now you can FindControl:
CheckBox cb = (CheckBox)Page.FindControl("chk" + j);