Detailsview in ASP.NET - asp.net

Question

I am trying to hit sql server with objectdatasource and return a datatable to fill my details view control. the selected ID value is returned by a gridview control. It seems like the datatable is not filled by adapter, and i couldn't figure out why. The ID in sql is set as a primary key (Int, 4, not null). The debugger says the Detail datatable is null. Any help is much appreciated.
public DataTable GetDetail(string ID)
{
if (ID == "")
{
return null;
}
else
{
DataTable Detail = null;
using (SqlConnection conn = new SqlConnection(connection))
{
string comm = #"select * from dbo.Products where ID = #ID";
conn.Open();
SqlDataAdapter adapter=null;
using (SqlCommand cmd = new SqlCommand(comm, conn))
{
cmd.Parameters.Add("ID", System.Data.SqlDbType.Int, 4).Value = Convert.ToInt32(ID);
adapter = new SqlDataAdapter(cmd);
adapter.Fill(Detail);
return Detail;
}
}
}

Answer 1

I think you missed the commandType
cmd.CommandType = CommandType.Text;

Answer 2

Try this
DataSet ds = new DataSet();
using (SqlConnection con = new SqlConnection(connection))
{
string myquery="select * from dbo.Products where ID = #ID";
SqlCommand cmd = new SqlCommand(myquery, con);
SqlDataAdapter dap = new SqlDataAdapter();
dap.SelectCommand = cmd;
cmd.Parameters.Add("#ID", SqlDbType.NVarChar, 15).Value = ID;
dap.Fill(ds);
return ds.Tables[0];
}

Answer 3

Thanks for ALL.
The problem is I didnt initialize my datatable to a new instance.
DataTable Detail = null; ===> DataTable Detail = new Datatable();
and also the convert should be done in sql not in codes.
cmd.Parameters.Add("ID", System.Data.SqlDbType.Int, 4).Value = ID;
string comm = #"select * from dbo.Products where ID = convert(int,#ID)";