您不使用文件输入控件。ASP.NET MVC中未使用服务器端控件。查看下面的博客文章，其中说明了如何在ASP.NET MVC中实现这一点。

因此，您将首先创建一个HTML表单，其中包含文件输入：

@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" name="file" />
    <input type="submit" value="OK" />
}

然后你会有一个控制器来处理上传：

public class HomeController : Controller
{
    // This action renders the form
    public ActionResult Index()
    {
        return View();
    }

    // This action handles the form POST and the upload
    [HttpPost]
    public ActionResult Index(HttpPostedFileBase file)
    {
        // Verify that the user selected a file
        if (file != null && file.ContentLength > 0) 
        {
            // extract only the filename
            var fileName = Path.GetFileName(file.FileName);
            // store the file inside ~/App_Data/uploads folder
            var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
            file.SaveAs(path);
        }
        // redirect back to the index action to show the form once again
        return RedirectToAction("Index");        
    }
}

在控制器中

 if (MyModal.ImageFile != null)
                    {
                        MyModal.ImageURL = string.Format("{0}.{1}", Guid.NewGuid().ToString(), MyModal.ImageFile.FileName.Split('.').LastOrDefault());
                        if (MyModal.ImageFile != null)
                        {
                            var path = Path.Combine(Server.MapPath("~/Content/uploads/"), MyModal.ImageURL);
                            MyModal.ImageFile.SaveAs(path);
                        }
                    }

在视图中

<input type="hidden" value="" name="..."><input id="ImageFile" type="file" name="ImageFile" src="@Model.ImageURL">

在模态类中

 public HttpPostedFileBase ImageFile { get; set; }

在项目的Content文件夹中创建上载文件夹

public ActionResult FileUpload(upload mRegister) {
    //Check server side validation using data annotation
    if (ModelState.IsValid) {
        //TO:DO
        var fileName = Path.GetFileName(mRegister.file.FileName);
        var path = Path.Combine(Server.MapPath("~/Content/Upload"), fileName);
        mRegister.file.SaveAs(path);

        ViewBag.Message = "File has been uploaded successfully";
        ModelState.Clear();
    }
    return View();
}

您不使用文件输入控件。ASP.NET MVC中未使用服务器端控件。查看下面的博客文章，其中说明了如何在ASP.NET MVC中实现这一点。

因此，您将首先创建一个HTML表单，其中包含文件输入：

@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" name="file" />
    <input type="submit" value="OK" />
}

然后你会有一个控制器来处理上传：

public class HomeController : Controller
{
    // This action renders the form
    public ActionResult Index()
    {
        return View();
    }

    // This action handles the form POST and the upload
    [HttpPost]
    public ActionResult Index(HttpPostedFileBase file)
    {
        // Verify that the user selected a file
        if (file != null && file.ContentLength > 0) 
        {
            // extract only the filename
            var fileName = Path.GetFileName(file.FileName);
            // store the file inside ~/App_Data/uploads folder
            var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
            file.SaveAs(path);
        }
        // redirect back to the index action to show the form once again
        return RedirectToAction("Index");        
    }
}

检查我的解决方案

public string SaveFile(HttpPostedFileBase uploadfile, string saveInDirectory="/", List<string> acceptedExtention =null)
{
    acceptedExtention = acceptedExtention ?? new List<String>() {".png", ".Jpeg"};//optional arguments

    var extension = Path.GetExtension(uploadfile.FileName).ToLower();

    if (!acceptedExtention.Contains(extension))
    {
        throw new UserFriendlyException("Unsupported File type");
    }
    var tempPath = GenerateDocumentPath(uploadfile.FileName, saveInDirectory);
    FileHelper.DeleteIfExists(tempPath);
    uploadfile.SaveAs(tempPath);

    var fileName = Path.GetFileName(tempPath);
    return fileName;
}

private string GenerateDocumentPath(string fileName, string saveInDirectory)
{
    System.IO.Directory.CreateDirectory(Server.MapPath($"~/{saveInDirectory}"));
    return Path.Combine(Server.MapPath($"~/{saveInDirectory}"), Path.GetFileNameWithoutExtension(fileName) +"_"+ DateTime.Now.Ticks + Path.GetExtension(fileName));
}

在基本控制器中添加这些函数，以便可以在所有控制器中使用它们

检查如何使用它

SaveFile(view.PassportPicture,acceptedExtention:new List<String>() { ".png", ".Jpeg"},saveInDirectory: "content/img/PassportPicture");

下面是一个完整的例子

[HttpPost]
public async Task<JsonResult> CreateUserThenGenerateToken(CreateUserViewModel view)
{// CreateUserViewModel contain two properties of type HttpPostedFileBase  
    string passportPicture = null, profilePicture = null;
    if (view.PassportPicture != null)
    {
        passportPicture = SaveFile(view.PassportPicture,acceptedExtention:new List<String>() { ".png", ".Jpeg"},saveInDirectory: "content/img/PassportPicture");
    }
    if (view.ProfilePicture != null)
    {
        profilePicture = SaveFile(yourHttpPostedFileBase, acceptedExtention: new List<String>() { ".png", ".Jpeg" }, saveInDirectory: "content/img/ProfilePicture");
    }
    var input = view.MapTo<CreateUserInput>();
    input.PassportPicture = passportPicture;
    input.ProfilePicture = profilePicture;


    var getUserOutput = await _userAppService.CreateUserThenGenerateToken(input);
    return new AbpJsonResult(getUserOutput);
    //return Json(new AjaxResponse() { Result = getUserOutput, Success = true });

}

使用formdata上载文件

.cshtml文件

     var files = $("#file").get(0).files;
     if (files.length > 0) {
                data.append("filekey", files[0]);}


   $.ajax({
            url: '@Url.Action("ActionName", "ControllerName")', type: "POST", processData: false,
            data: data, dataType: 'json',
            contentType: false,
            success: function (data) {
                var response=data.JsonData;               
            },
            error: function (er) { }

        });

服务器端代码

if (System.Web.HttpContext.Current.Request.Files.AllKeys.Any())
                {
                    var pic = System.Web.HttpContext.Current.Request.Files["filekey"];
                    HttpPostedFileBase filebase = new HttpPostedFileWrapper(pic);
                    var fileName = Path.GetFileName(filebase.FileName);


                    string fileExtension = System.IO.Path.GetExtension(fileName);

                    if (fileExtension == ".xls" || fileExtension == ".xlsx")
                    {
                        string FileName = Guid.NewGuid().GetHashCode().ToString("x");
                        string dirLocation = Server.MapPath("~/Content/PacketExcel/");
                        if (!Directory.Exists(dirLocation))
                        {
                            Directory.CreateDirectory(dirLocation);
                        }
                        string fileLocation = Server.MapPath("~/Content/PacketExcel/") + FileName + fileExtension;
                        filebase.SaveAs(fileLocation);
}
}