Merge two data tables with the same structure under asp. ent

Wrote a function.
Copy codeThe Code is as follows:
/// <Summary>
/// Merge two identical datatables and return the Merged Results
/// </Summary>
/// <Param name = "dt1"> </param>
/// <Param name = "dt2"> </param>
/// <Returns> </returns>
Public DataTable CombineTheSameDatatable (DataTable dt1, DataTable dt2)
{
If (dt1.Rows. Count = 0 & dt2.Rows. Count = 0)
{
Return new DataTable ();
}
If (dt1.Rows. Count = 0)
{
Return dt2;
}
If (dt2.Rows. Count = 0)
{
Return dt1;
}
DataSet ds = new DataSet ();
Ds. Tables. Add (dt1.Copy ());
Ds. Merge (dt2.Copy ());
Return ds. Tables [0];
}

Due to the limited understanding of C #, I don't know why I cannot correctly judge the empty table with dt1 = null, so I used the method of several rows.