System.IO.FileNotFoundException: 未能找到文件“C:\sms_old.txt”。
文件名:“C:\sms_old.txt”
   在 System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   在 System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   在 System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   在 System.IO.StreamReader..ctor(String path, Encoding encoding, Boolean detectEncodingFromByteOrderMarks, Int32 bufferSize, Boolean checkHost)
   在 System.IO.File.InternalReadAllText(String path, Encoding encoding, Boolean checkHost)
   在 Soccer.Default.Page_Load(Object sender, EventArgs e)