C# 创建文件并往文件里写内容

 protected void btnCreate_Click(object sender, EventArgs e)
        ...{
            string path = HttpContext.Current.Request.PhysicalPath;
            string file = path.Substring(0,path.LastIndexOf("/")+1) + @"命令.bat";
            if (File.Exists(file))
            ...{
                StreamWriter sw = File.AppendText(file);
                sw.WriteLine("net state");
                sw.Close();       //关闭流
                sw.Dispose();    //销假对象
            }
            else
            ...{
                StreamWriter sw = File.CreateText(file);
                sw.WriteLine("dir");
                sw.Close();
                sw.Dispose();
            }
        }