如何从 MVC 5 中的 FileResult 和锚标记下载文件？

Question

这是我的文件上传和下载代码

 [HttpPost]
    public ActionResult Save(Rent Rent , FileUpload upload, HttpPostedFileBase file)
    {

        if (Rent.Id == 0)
            _Context.Rent.Add(Rent);

        else
        {
            var rentInDb = _Context.Rent.Single(c => c.Id == Rent.Id);

            rentInDb.tenantId = Rent.tenantId;
            rentInDb.unitId = Rent.unitId;
            rentInDb.startDate = Rent.startDate;
            rentInDb.endDate = Rent.endDate;
            rentInDb.Amount = Rent.Amount;
            rentInDb.leaseStatus = Rent.leaseStatus;


        }

            _Context.SaveChanges();

        var rent = _Context.Rent.Single(r => r.Id == Rent.Id);

        var up = Request.Files["file"];
        if (up.ContentLength > 0) {



            var fileName = Path.GetFileName(file.FileName);
            var guid = Guid.NewGuid().ToString();
            var path = Path.Combine(Server.MapPath("~/uploads"), guid + fileName);
            file.SaveAs(path);
            string fl = path.Substring(path.LastIndexOf("\"));
            string[] split = fl.Split('\');
            string newpath = split[1];
            string imagepath = "~/uploads/" + newpath;
            upload.length = imagepath;
            upload.Rent = rent;
            _Context.FileUpload.Add(upload);
            _Context.SaveChanges();

        }
        return RedirectToAction("leaseStatus", "Home");
    }


 public ActionResult Downloads(int id)
    {
        var fl = _Context.FileUpload.Where(f => f.rentId == id);
        var up = Request.Files["file"];




        return View(fl );
    }

public FileResult Download(string ImageName)
  {
          var FileVirtualPath = "~/uploads/" + ImageName;

        return File(FileVirtualPath, "application/force-download", Path.GetFileName(FileVirtualPath));


}

这是我的观点！！

@model IEnumerable<mallform.Models.FileUpload>
@{
    ViewBag.Title = "Downloads";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Downloads</h2>


@foreach (var file in Model)
{
   

    

    <a href=@file.length target="_blank">Download</a>

}

这显示标准 404.0 和有时隐藏元素错误 :( 请帮忙。在我的代码中，它包括上传文件代码，然后有一个下载操作导致我下载视图，在下载视图中，我有一个 link 按文件结果下载文件。但它总是向我显示错误。请告诉我路径是否有问题或发生了什么？

Answer 1

文件结果操作应该是这样的。

public FileResult Download(string ImageName)
{

    byte[] fileBytes = System.IO.File.ReadAllBytes(Server.MapPath(@"~/uploads/"+ImageName));
   string fileName = "myfile."+Path.GetExtension(Server.MapPath(@"~/uploads/"+ImageName));
return File(fileBytes, System.Net.Mime.MediaTypeNames.Application.Octet, fileName);


}

Answer 2

Error Code 404 means the url is not found by your anchor tag. https://en.wikipedia.org/wiki/HTTP_404

您需要将 ImageName 参数从锚标记传递到控制器。你可以这样做：

查看

@model IEnumerable<mallform.Models.FileUpload>
@{
    ViewBag.Title = "Downloads";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Downloads</h2>


@foreach (var file in Model)
{

    @Html.ActionLink(
          "Download File",              // Anchor Text
          "Download",                   // Action Name 
          "Controller Name",            // Controller Name
           new {                 
                 ImageName= "Pass the value of imagename parameter"
               },
           null         // Html Attributes
          )
}

控制器

    public FileResult Download(string ImageName)
      {
     //var FileVirtualPath = "~/uploads/" + ImageName; 

    //If using Physical Path  
    //var FileVirtualPath = HttpContext.Current.Request.MapPath("~/uploads/" + ImageName); 

    //If using Virtual Path
     var FileVirtualPath = HttpContext.Current.Server.MapPath("~/uploads/" + ImageName);   

     return File(FileVirtualPath, "application/force-download", Path.GetFileName(FileVirtualPath));

    }

如何从 MVC 5 中的 FileResult 和锚标记下载文件？

How To Download A file From FileResult and anchor tag in MVC 5?

c#

asp.net-mvc

file-upload

fileresult

asp.net-mvc-5