如何将字符串写入XML文件问题

我获取字符串源码如下：
C# code:

public static string Hotpic()

{
DataSet Hotpic = NewsManager.GetList(5, "ispic=0", "newsdate desc");
string picnews = "<?xml version=\"1.0\" encoding=\"utf-8\"?><data><channel>";
if (Hotpic.Tables[0].Rows.Count > 0)
{
for (int i=0; i < Hotpic.Tables[0].Rows.Count; i++)
{
picnews += "<item><title>";
picnews += Hotpic.Tables[0].Rows[i]["title"].ToString();
picnews += "</title></item>";
}
picnews +="</data></cannel>";
}
return Hotpic.ToString ();



在页面中的调用：
C# code:

protected void Page_Load(object sender, EventArgs e)
{
string hotpic = "";
hotpic = Readpicnews .Hotpic ();
System.Xml.XmlDocument dc = new XmlDocument();
dc.Load(hotpic);
dc.Save("C:\\student.XML");

}





老