How to use DataBinding to set the ID of asp:CheckBox controls - asp.net

Question

I have some ASP that I want to look kinda of like this:
<asp:DataGrid ID="dgEnum" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:TemplateColumn>
<ItemTemplate>
<asp:CheckBox ID="<%# some big DataBinder expression %>" runat="server" />
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
but that gives me a:
Parser Error Message: The ID property of a control can only be set using the ID attribute in the tag and a simple value. Example: <asp:Button runat="server" id="Button1" />
Anyone have an idea how to hack around that?

Answer 1

Anyone have an idea how to hack around that?
You can't, and you don't. You can store the required data somewhere besides the ID. At the very least, a sibling HiddenField could be used.
<script runat="server">
void Checkbox_CheckedChanged(object sender, EventArgs e) {
var c = (Checkbox)sender;
if (!c.Checked) {
return;
}
var hfv = (HiddenField)c.Parent.FindControl("hfvMyData");
var myData = hfv.Value;
/* Do something with myData */
}
</script>
<asp:DataGrid ID="dgEnum" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:TemplateColumn>
<ItemTemplate>
<asp:CheckBox runat="server" OnCheckedChanged="Checkbox_CheckedChanged" />
<asp:HiddenField id="hfvMyData" runat="server" Value='<%# Eval("MyData") %>' />
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
Other options could be DataKeys, a server side (perhaps cached or Session data) indexed list, or a ViewState indexed list.
If you really wanted to bastardize WebForms, you can put your data into CssClass...but that's just crazy. ;)

Answer 2

Not sure what you are intending to do here, but you can just go straight to the html controls ie <input type="checkbox" id="<%# some expresssion %>" />
Or you don't do this and query for it on the server side. I.e. find the row you want and then use FindControls() to get the checkbox for that row.