The AssociatedHeaderCellID property contains a list of header cell programmatic identifiers that provide header information of the TableCell control. The list of header cell identifiers is rendered as a comma delimited list into the HTML <td> element's header attribute.
When setting the AssociatedHeaderCellID property use a comma delimited list of strings. If an element of the list is not recognized as a valid table header cell an HttpException is thrown when the AddAttributesToRender is invoked.
The following code example demonstrates how to declaratively specify the AssociatedHeaderCellID property of a TableCell control. In particular, note how the cell in the last row is associated to three header cells. For a complete, working code example, see the TableHeaderCell class overview topic.