Custom Control in Asp.Net C#

See more:

C#

I want to create Custom dropdown Control in Asp.Net in which i want to show multiple checkbox in 3 column. I have created, but it displays only one column checkbox, can any1 help me pz?

<script language="javascript" type="text/javascript">
        function showdiv() {
            document.getElementById("divChkList").style.display = "block";
        }
        function showdivonClick() {
            var objDLL = document.getElementById("divChkList");
            if (objDLL.style.display == "block")
                objDLL.style.display = "none";
            else
                objDLL.style.display = "block";
        }
        function getSelectedItem(lstValue, lstNo, lstID, ctrlType) {
            var noItemChecked = 0;
            var ddlReport = document.getElementById("ddlChkList");
            var selectedItems = "";
            var arr = document.getElementById("chkLstItem").getElementsByTagName('input');
            var arrlbl = document.getElementById("chkLstItem").getElementsByTagName('label');
            var objLstId = document.getElementById('hidList');
            for (i = 0; i < arr.length; i++) {
                checkbox = arr[i];
                if (i == lstNo) {
                    if (ctrlType == 'anchor') {
                        if (!checkbox.checked) {
                            checkbox.checked = true;
                        }
                        else {
                            checkbox.checked = false;
                        }
                    }
                }
                if (checkbox.checked) {
                    if (selectedItems == "") {
                        selectedItems = arrlbl[i].innerText;
                    }
                    else {
                        selectedItems = selectedItems + "," + arrlbl[i].innerText;
                    }
                    noItemChecked = noItemChecked + 1;
                }
            }
            ddlReport.title = selectedItems;
            var Text = ddlReport.options[ddlReport.selectedIndex].text;
            if (noItemChecked == 1)
                ddlReport.options[ddlReport.selectedIndex].text = lstValue;
            else
                ddlReport.options[ddlReport.selectedIndex].text = noItemChecked + " Items";
            document.getElementById('hidList').value = ddlReport.options[ddlReport.selectedIndex].text;
        }

        document. önclick = check;
        function check(e) {
            var target = (e && e.target) || (event && event.srcElement);
            var obj = document.getElementById('divChkList');
            var obj1 = document.getElementById('ddlChkList');
            if (target.id != "alst" && !target.id.match("chkLstItem")) {
                if (!(target == obj || target == obj1)) {
                    obj.style.display = 'none'
                }
                else if (target == obj || target == obj1) {
                    if (obj.style.display == 'block') {
                        obj.style.display = 'block';
                    }
                    else {
                        obj.style.display = 'none';
                        document.getElementById('ddlChkList').blur();
                    }
                }
            }
        }

C# code

protected void Page_Load(object sender, EventArgs e)
    {
        DropDownList ddl = new DropDownList();
        ddl.ID = "ddlChkList";
        ListItem lstItem = new ListItem();
        ddl.Items.Insert(0, lstItem);
        ddl.Width = new Unit(155);
        ddl.Attributes.Add("onmousedown", "showdivonClick()");
        CheckBoxList chkBxLst = new CheckBoxList();
        chkBxLst.ID = "chkLstItem";
        chkBxLst.Attributes.Add("onmouseover", "showdiv()");
        DataTable dtListItem = GetListItem();
        int rowNo = dtListItem.Rows.Count;
        string lstValue = string.Empty;
        string lstID = string.Empty;
        for (int i = 0; i < rowNo - 1; i++)
        {
            lstValue = dtListItem.Rows[i]["Value"].ToString();
            lstID = dtListItem.Rows[i]["ID"].ToString();
            lstItem = new ListItem("< chk.Items.Count; i++)
        {
            if (chk.Items[i].Selected)
            {
                if (strSelectedItem.Length == 0)
                {
                    strSelectedItem = chk.Items[i].Selected.ToString();
                }
                else
                {
                    strSelectedItem = strSelectedItem + "," + chk.Items[i].Selected.ToString();
                }
            }
        }
        ddl.Items.Clear();
        ddl.Items.Add(new ListItem(hidList.Value));
        lblSelectedItem.Text = strSelectedItem;
    }

    public DataTable GetListItem()
    {
        DataTable table = new DataTable();
        table.Columns.Add("ID", typeof(int));
        table.Columns.Add("Value", typeof(string));
        table.Rows.Add(1, "ListItem1");
        table.Rows.Add(2, "ListItem2");
        table.Rows.Add(3, "ListItem3");
        table.Rows.Add(4, "My ListItem Wraps also");
        table.Rows.Add(5, "My New ListItem5");
        table.Rows.Add(6, "ListItem6");
        table.Rows.Add(7, "ListItem7");
        table.Rows.Add(8, "ListItem8");
        return table;
    }