为什么生成的XML支持中文呢!!

{ string sql = " select * from Sys_Area ";
//连接数据库生成dataSet
DataSet ds = HengXian.DbHelperSQL.DbHelperSQL.Query(sql);
string s= " <?xml version=\ "1.0\ " encoding=\ "utf-8\ " standalone=\ "yes\ "?> \r\n ";
s+= " <?xml-stylesheet type=\ "text/xsl\ " href=\ "a.xsl\ "?> \r\n ";
s += " <item> " + "\r\n ";
for (int i = 0; i < ds.Tables [0].Rows.Count; i++)
{
//ds.Tables[0].Rows[i][ "AreaName "].ToString() 为中文
s += " " + " <item Text=\ " " + ds.Tables[0].Rows[i][ "AreaName "].ToString() + "\ " " + " ";
s += "NavigateUrl=\ " " + "overlapping_edges.aspx+ "+ "kk " + "\ " "+ " ";
s += "DefaultSubItemLookId = \ "Level2Tab\ " ";
s += " DefaultSubItemSelectedLookId =\ "SelectedLevel2Tab\ " > "+ "\r\n ";
s += " "+ " <item Text=\ "Top Stories\ " NavigateUrl=\ "overlapping_edges.aspx?page=top_stories\ " /> " + "\r\n ";
s += " " + " </item> " + "\r\n ";
}
s += " </item> > ";

string filename = "feng ";

StreamWriter sw=new StreamWriter( Server.MapPath( " ")+ "/ "+filename+ ".xml ",false,System.Text.Encoding.GetEncoding( "GB2312 "));
sw.Write(s);
sw.Close();
}


下面是结果:
<?xml version= "1.0 " encoding= "utf-8 " standalone= "yes "?>
<?xml-stylesheet type= "text/xsl " href= "a.xsl "?>
<item>


<item Text= "ڹ�� " NavigateUrl= "overlapping_edges.aspx=1kk " DefaultSubItemLookId = "Level2Tab " DefaultSubItemSelectedLookId = "SelectedLevel2Tab " >
<item Text= "Top Stories " NavigateUrl= "overlapping_edges.aspx?page=top_stories " />
</item>

</item>


请问是什么回事啦!!Text= "ڹ�� " 我要生成的可是中文啦!!


[解决办法]
try:StreamWriter sw=new StreamWriter( Server.MapPath( " ")+ "/ "+filename+ ".xml ",false,System.Text.Encoding.Utf8); sw.Write(s); sw.Close();