清空文件内容

FileStream stream2 = File.Open(inforpath, FileMode.OpenOrCreate, FileAccess.Write);
stream2.Seek(0, SeekOrigin.Begin); //第一行代码将文件指针移动到文件的第0个字节。
stream2.SetLength(0); //清空txt文件
stream2.Close();
File.WriteAllLines(PathBase + inforpath, content1);