For a description of this member, see IPersistedSelector.DataKey.
Assembly: System.Web (in System.Web.dll)
You can specify how selected rows are persisted when the GridView control is in paging mode. By default, row selection is based on row index. The same row (for example, the third row) is selected on each page. Alternatively, you can enable persistence based on the data key of the selected row. In that case, if you select row 3 on page 1 and you move to page 2, no row is selected on page 2. If you move back to page 1, row 3 is still selected. To enable this functionality, set this property to true.
In versions 2.0, 3.0, and 3.5 of ASP.NET, row selection was based only on row index. By default, row selection in ASP.NET 4 is based on index for backward compatibility.