在ASP.NET内核中流式传输文件后如何删除该文件

using System;
using System.IO;
using System.Web.Mvc;

public class FileController : Controller
{
    public ActionResult DownloadFile(string filePath)
    {
        if (System.IO.File.Exists(filePath))
        {
            // 创建一个文件流
            using (FileStream fs = new FileStream(filePath, FileMode.Open))
            {
                // 设置响应头
                Response.ContentType = "application/octet-stream";
                Response.AddHeader("Content-Disposition", "attachment; filename=" + Path.GetFileName(filePath));

                // 将文件流写入响应
                fs.CopyTo(Response.OutputStream);

                // 关闭响应流
                Response.Flush();
            }

            // 删除文件
            System.IO.File.Delete(filePath);

            return new EmptyResult();
        }
        else
        {
            return new HttpNotFoundResult();
        }
    }
}