add new row to gridview with C#

User below code,

DataTable dt = new DataTable();
DataRow dr = null;
dt.Columns.Add(new DataColumn("RowNumber", typeof(string)));
dt.Columns.Add(new DataColumn("Col1", typeof(string)));
dt.Columns.Add(new DataColumn("Col2", typeof(string)));
dt.Columns.Add(new DataColumn("Col3", typeof(string)));
dt.Columns.Add(new DataColumn("Col4", typeof(string)));
dt.Columns.Add(new DataColumn("Col5", typeof(string)));
dr = dt.NewRow();
dr["RowNumber"] = 1;
dr["Col1"] = string.Empty;
dr["Col2"] = string.Empty;
dr["Col3"] = string.Empty;
dr["Col4"] = string.Empty;
dr["Col5"] = string.Empty;
dt.Rows.Add(dr);

I think its work.