读取TXT文件到指定的控件

  string path = Server.MapPath("~\\App_Data\\" + sName + ".txt");
  StreamReader sr = new StreamReader(path, Encoding.Default);
  this.labHelp.Text = sr.ReadLine();
  this.txtRead.Text = sr.ReadToEnd();
  sr.Close();

可能需要引入的包

using System.IO;
using System.Text;