How to programmatically Select (Check) Unselect (Uncheck) Items of CheckBoxList in ASP.Net

Hi @manvendra45

You can not user delete option inside label control.

For doing this you need a data control such as GridView. Refer this code.

HTML

   <div>
    <asp:CheckBoxList ID="CheckBoxList1" runat="server" AutoPostBack="True" 
            onselectedindexchanged="CheckBoxList1_SelectedIndexChanged">
          <asp:ListItem Value="0">C#</asp:ListItem>
          <asp:ListItem Value="1">SQL Server</asp:ListItem>
          <asp:ListItem Value="2">ASP.NET</asp:ListItem>
          <asp:ListItem Value="3">WPF</asp:ListItem>
      </asp:CheckBoxList>
      <br />
      
      <br />
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
            ShowHeader="False" onrowdeleting="GridView1_RowDeleting">
            <Columns>
                <asp:BoundField DataField="Language" SortExpression="Language" />
                <asp:TemplateField>
                <ItemTemplate>
                    <asp:LinkButton ID="lnkdelete" runat="server" CommandName="Delete" OnClientClick="return confirm('Are you sure to Delete ?')">Delete</asp:LinkButton>
                </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
  </div>

Required NameSpace

Using System.Data;

C#

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add(new DataColumn("Language", typeof(string)));
            ViewState["CurrentTable"] = dt;
        }
    }
    protected void CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        CreateGrid();
    }
    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        string language = GridView1.Rows[e.RowIndex].Cells[0].Text;
        foreach (ListItem lst in CheckBoxList1.Items)
        {
            if (lst.Text == language)
            {
                lst.Selected = false;
            }
        }
        CreateGrid();
    }

    private void CreateGrid()
    {
        if (ViewState["CurrentTable"] != null)
        {
            DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
            foreach (ListItem lst in CheckBoxList1.Items)
            {
                if (lst.Selected == true)
                {
                    DataRow row = dtCurrentTable.NewRow();
                    row["Language"] = lst.Text;
                    dtCurrentTable.Rows.Add(row);
                }
            }
            ViewState["CurrentTable"] = dtCurrentTable;
            GridView1.DataSource = dtCurrentTable;
            GridView1.DataBind();
            dtCurrentTable.Rows.Clear();
        }
    }