//请参考下面的例子

void Page_Load(){
.

Response.Charset="";
this.EnableViewState =false;
StringWriter tw=new StringWriter();
HtmlTextWriter wt =new HtmlTextWriter(tw);

string path=@"c:\test.htm";
//FileInfo info =new FileInfo(@"c:\test.txt");


StreamWriter wter = File.CreateText(path);


//输出所有信息
this.RenderControl(wt);
wter.Write(tw.ToString());
//Response.Write(tw.ToString());
wter.Close();

wt.Close();
tw.Close();
Response.End();
//生成相应文件，然后定向到该文件
Response.Redirect(path);
}