C#中使用简单的线程

    protected void btn_Click(object sender, EventArgs e)
    {
        String dir = "C:/Documents and Settings/Administrator/桌面/新建文件夹";
        Thread t = new Thread(DeleteDir);
        t.Start(dir);

        DirectoryInfo d = new DirectoryInfo("C:/Documents and Settings/Administrator/桌面/新建文件夹 (2)");
        if (d.GetFiles().Length == 0) {
            Directory.Delete("C:/Documents and Settings/Administrator/桌面/新建文件夹 (2)");
        }       
    }

    static void DeleteDir(object dir)
    {
        Thread.Sleep(10000);
        Directory.Delete(dir.ToString());
    }