Phần View
Mã:
@using (Html.BeginForm("UpdateImage","UploadFile",FormMethod.Post, new { enctype = "multipart/form-data"})) 
{
    <div>
        <label for="fileUpload">File upload</label>
        <input type="file" id="fileUpload" name="fileUpload" />
    </div>
    <div>
        <input type="submit" value="Submit" />
    </div>
}
Phần Controller
Mã:
 public ActionResult UploadFile()
{
     return View();
}

[HttpPost]
public ActionResult UploadFile()
{
    foreach (string upload in Request.Files)
    {
         if (Request.Files[upload].ContentLength == 0) continue;
         string pathToSave = Server.MapPath("~/Content/Images/");//Phần vị trí lưu File .
         string filename = Path.GetFileName(Request.Files[upload].FileName);
         Request.Files[upload].SaveAs(Path.Combine(pathToSave, filename));
         ModelState.AddModelError("", "Update thanh cong");
    }
    return View();
}