MVC文件上传和下载

1.单个文件上传

HTML写法：form表单中加enctype="multipart/form-data" 

<form aciont="" method="post" enctype="multipart/form-data">
    <input type="file" id="file" name="file" />
    <br/>
    <input type="submit" name="提交"/>
</form>

View写法：同样 form表单中加enctype="multipart/form-data" 

@using (Html.BeginForm("Add", null, FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" id="file" name="file" />
    <br/>
    <input type="submit" value="提交"/>
}

后台Controller中的写法：

[HttpPost]
public ActionResult Add(HttpPostedFileBase file)
{
    string path = "/uploadImg/";
   if (!Directory.Exists(Server.MapPath(path)))
   {
        Directory.CreateDirectory(Server.MapPath(path));
   }
   if (file != null)
   {
       string filePath = string.Format("{0}/{1}{2}", path, System.Guid.NewGuid(), System.IO.Path.GetExtension(file.FileName));
       file.SaveAs(Server.MapPath(filePath));
   }  
   return View();
 }

2.多个文件上传

就是form表单中多个input file 

@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" id="file" name="file1" />
    <input type="file" id="file" name="file2" />
    <input type="file" id="file" name="file3" />
    <input type="file" id="file" name="file4" />
    <input type="file" id="file" name="file5" />
    <input type="file" id="file" name="file6" />
    <br/>
    <input type="submit" value="提交"/>
}

public class HomeController:Controller
{
 public ActionResult Index()
  {
    foreach (string upload in Request.Files)
    {
      if (!Request.Files[upload].HasFile()) continue;
      string path = "/uploadImg/";
      string filename = Path.GetFileName(Request.Files[upload].FileName);
      Request.Files[upload].SaveAs(Path.Combine(path, filename));
    }
    return View();
  }
 }

3.文件下载

HTML中：<a href="/GetFile">下载文件</a>
View中：@Html.ActionLink("下载文件", "Download", "Home");

直接下载到默认下载中

 

 public class HomeController : Controller
    {
     public FilePathResult GetFileFromDisk()
        {
            string path = @"/uploadImg/";
            string fileName = "5141fb63-955b-4f0b-9f53-ab770329e6f5.png";
            return File(path + fileName, "image/png", fileName);
        }

        public FileStreamResult StreamFileFromDisk()
        {
            string path = AppDomain.CurrentDomain.BaseDirectory + "uploadImg/";
            string fileName = "5141fb63-955b-4f0b-9f53-ab770329e6f5.png";
            return File(new FileStream(path + fileName, FileMode.Open), "image/png", fileName);
        }
    }
}