Disable CheckBox inside GridView once Checked in ASP.Net

For the CheckBox add CheckChanged event and say AutoPostBack true and simply disable it and on Button click enable it

 <asp:GridView ID="gvDemo" runat="server" AutoGenerateColumns="false">
        <Columns>
            <asp:TemplateField>
                <ItemTemplate>
                    <asp:CheckBox ID="CheckBox1" Text="CheckBox" runat="server" OnCheckedChanged="OnCheckedChanged"
                        AutoPostBack="true" />
                </ItemTemplate>
            </asp:TemplateField>
            <asp:BoundField DataField="Code" HeaderText="Code" />
            <asp:BoundField DataField="Name" HeaderText="Name" />
              <asp:TemplateField>
                <ItemTemplate>
                    <asp:Button Text="Submit" runat="server" OnClick = "EnableCheckBox" />
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            DataTable dt = new DataTable();
            dt.Columns.AddRange(new DataColumn[2]{ 
                            new DataColumn("Code", typeof(int)), 
                            new DataColumn("Name", typeof(string))  });
            dt.Rows.Add(1, "Jake");
            dt.Rows.Add(2, "John");
            dt.Rows.Add(3, "Micheal");
            gvDemo.DataSource = dt;
            gvDemo.DataBind();
        }
    }
 protected void OnCheckedChanged(object sender, EventArgs e)
    {
        (sender as CheckBox).Enabled = false;
    }
    protected void EnableCheckBox(object sender, EventArgs e)
    {
        CheckBox chk = (sender as Button).NamingContainer.FindControl("CheckBox1") as CheckBox;
        chk.Enabled = true;
        chk.Checked = false;
    }