WCF服务在本地主机中执行，但在IIS中托管时比不工作

Question

当我手动调试时，我的WCF服务工作正常，但是当我在IIS中托管相同的服务时，将托管服务的链接添加到我的Web应用程序然后服务被执行但是它没有创建我的文件想。这是我的WCF服务代码。

public void Deploy(string clientName)
{
    string folderpath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + "\\" + "WCFFilesForIISHosting" + "\\";
    if (!Directory.Exists(folderpath))
    {
        Directory.CreateDirectory(folderpath);
    }
    DirectoryInfo di = new DirectoryInfo(folderpath);
    FileInfo[] files = di.GetFiles("*.txt").Where(p => p.Extension == ".txt").ToArray();

    TextWriter tw;
    string text = clientName;

    string path = folderpath + "Clients" + ".txt";
    if (!File.Exists(path))
    {
        File.Create(path).Dispose();
        tw = new StreamWriter(path);
        tw.WriteLine(text.ToString()+Environment.NewLine);
        tw.Close();
    }
    else
    {
        File.AppendAllText(path, text.ToString()+Environment.NewLine);
    }
}