StreamWriter Problem

Code:

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if (File.Exists("\\Program Files\\ContorPDA\\Apro.xml"))
                {
                    File.Delete("\\Program Files\\ContorPDA\\Apro.xml");
                }
                StreamWriter swc= File.CreateText(@"\Program Files\ContorPDA\Apro.xml");
                string rez = string.Empty;
                rez += "<?xml version='1.0'?>" + "\r\n";
                rez += "<Aparate>" + "\r\n";
                swc.Write(rez);
                SqlCeCommand apro = Biblio.pCon.CreateCommand();
                apro.CommandText = "SELECT  '<Aparat Id=\"'+ CONVERT(nvarchar,id_aparat) + '\" Cafea=\"' + cafea + " +
                                  " '\"  Ciocolata=\"' + ciocolata + " +
                                  " '\" Ceai=\"' + ceai + " +
                                  " '\" Palete=\"' + palete + " +
                                  " '\" Pahare=\"' + pahare + " +
                                  " '\" Lapte=\"' + lapte + " +
                                  " '\" Zahar_personalizat=\"' + zahar_pers + " +
                                  " '\" Zahar=\"' + zahar + " +
                                  " '\" NessCaffe=\"' + nesscaffe + '\" />'" +
                                  " FROM Cantitati ";
                SqlCeResultSet aproscr = apro.ExecuteResultSet(ResultSetOptions.Scrollable);
                rez += string.Empty;
                while (aproscr.Read())
                {
                 
                  rez += aproscr.GetValue(0) + "\r\n";
                 
                }
               
             
                rez += "</Aparate>" + "\r\n";
                swc.Write(rez);

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i use this code to save from sql mobile to xml but it doesn't write ito the file
I put a breakpoint at the last rez ant it contains the data i need. But it doesnt write,just creates an empty file
if i put in while swc.Write(rez) it writes into the file but not as i want them to be .What i do wrong?

i did it
i put swc.Close() at the end