How to generate the data from gridview to excel

Question

How to generate the data from grid view to excel

 

My Requirement is 

 

How to generate the data from gridview to excel 

i created my datatable 

 

i need to generate the data randomly when i click the button to the excel

 

below u can find the code

 

private DataTable GetDetails(int id)

{

_dt = new DataTable();

_da = new SqlDataAdapter("sp_GetDetails", _con);

_da.SelectCommand.Parameters.AddWithValue("@id", id);

_da.SelectCommand.CommandType = CommandType.StoredProcedure;

_dt.Clear();

_da.Fill(_dt);

return _dt;

}

 

please help me this 

 

Thanks