怎么复制一个SqlDataReader

string cnn = ConfigurationManager.ConnectionStrings["ReportDataService"].ConnectionString;
using (SqlConnection cn = new SqlConnection())
{
cn.ConnectionString = cnn;
cn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = cn;
cmd.CommandText = "p_OrderDetailExecute";
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@SupplierID", SupplierID);
using (var reader = cmd.ExecuteReader())