ASP.NET中CheckBox控件的点击与取消事件（DataList控件中）

<asp:CheckBox ID="chBookStation" runat="server" Checked ='<%#(bool)DataBinder.Eval( Container .DataItem ,"GbAnonyMity")?true:false%>' AutoPostBack="true" ForeColor="Blue" oncheckedchanged="chBookStation_CheckedChanged" ToolTip='<%#DataBinder.Eval( Container .DataItem ,"GbID") %>' />

protected void chBookStation_CheckedChanged(object sender, EventArgs e)
        {
            try
            {
                CheckBox cbBookInStaion = (CheckBox)sender;
                string bookId = cbBookInStaion.ToolTip;
                //string roleName = cbBookInStaion.Attributes["role"];
                if (!cbBookInStaion.Checked && bookId != null)
                {
                    GuestBooks guestBooks = new GuestBooks();
                    guestBooks.AmendOneBookStaion(bookId, 0);
                    DataList1.DataSource = guestBooks.ShowBook20New(0);
                    DataList1.DataBind();
                }
                else if (bookId != null)
                {
                    GuestBooks guestBooks = new GuestBooks();
                    guestBooks.AmendOneBookStaion(bookId, 1);
                    DataList1.DataSource = guestBooks.ShowBook20New(0);
                    DataList1.DataBind();
                }
                Page.RegisterStartupScript("", "<script>alert('更新成功!')</script>");
            }
            catch
            {
                Page.RegisterStartupScript("", "<script>alert('更新失败!')</script>");
            }
        }