Question

My WebService running on WebApplication and WinApplication. And no error.
Service like :

public DataTable foo(string UserID)
{
...
}

But DataTable returned null on WindowsCE. Why? But everything is normal.
WinCE code is :

DataTable dt = serv.getList(txt, SType.SNo, ref eg, ref ew, ref et);

All ref field is correct, but dt.rows=0 ??

Thanks for help.

Answer 1

DataTables cannot be serialized over an XML web service. From the Microsoft Knowledge Base:

“The DataTable, DataRow, DataView, and DataViewManager objects cannot be serialized and cannot be returned from an XML Web service. To return less than a complete DataSet, you must copy the data that you want to return to a new DataSet.”