I get an error as [ Object reference not set ....] when i try to submit a form to store some values and the path of an uploaded image into database

Question

I have a form to store some records in events table in database along with the path of an uploaded file.

But when i click the Save button, it generates the following error:

Object reference not set to an instance of an object.

This is my model:

public class events1
{
    public int Id { get; set; }
    public string title { get; set; }
    public string report { get; set; }
    public string image1 { get; set; }
    public string image2 { get; set; }

    [NotMapped]
    public HttpPostedFileBase ImageFile { get; set; }
}

This is my controller

    public ActionResult Index()
    {
        var evt = _context.evt1;
        if (evt==null)
        {
            return Content("No events registered in database");
        }
        return View(evt);
    }



    public ActionResult Add_New()
    {

        return View();
    }

    [HttpPost]
    public ActionResult Save(events1 e)
    {

        string filename = Path.GetFileNameWithoutExtension(e.ImageFile.FileName);
        string extension = Path.GetExtension(e.ImageFile.FileName);
        filename = filename + DateTime.Now.ToString("yymmssfff") + extension;
        e.image1 = "~/Uploaded_Files/" + filename;
        filename = Path.Combine(Server.MapPath("~/Uploaded_Files/"), filename);
        e.ImageFile.SaveAs(filename);



        _context.evt1.Add(e);
        _context.SaveChanges();
        ModelState.Clear();

        return RedirectToAction("Index","Events1");
    }

And this is the view:

   @model UploadFile_Button.Models.events1
@{
ViewBag.Title = "Add_New";
Layout = "~/Views/Shared/_Layout.cshtml";
 }

 @using (Html.BeginForm("Save", "Events1"))

 {
<div class="form-group">
    @Html.LabelFor(a => a.title)
    @Html.TextBoxFor(a => a.title, new { @class = "form-control" })
</div>
<div class="form-group">
    @Html.LabelFor(a => a.report)
    @Html.TextBoxFor(a => a.report, new { @class = "form-control" })
</div>
<div class="form-group">
   <input type="file" name="ImageFile"/>
</div>
<div class="form-group">
    @Html.LabelFor(a => a.image2)
    @Html.TextBoxFor(a => a.image2, new { @class = "form-control" })
</div>
<button type="submit" class="btn btn-primary">Save</button>
}

I have to mention when it generates the error, it also highlights this line of my code in RED color:

string filename = Path.GetFileNameWithoutExtension(e.ImageFile.FileName);

Answer 1

This is happening because some line in your action method for Save is throwing an exception i.e. run time error. The error Object reference not set to an instance of an object means some object in your Save method is null and your code is trying to call a method on this null object. Most likely, its some object in the line that you have mentioned. (NOTE: Remember that a method can never be called on an object that is null.)

string filename = Path.GetFileNameWithoutExtension(e.ImageFile.FileName);

To prevent this error from occurring make sure that a valid parameter is being passed to your action method of Save and also check in the same same method if object e is null or object ImageFile is null before running remaining code in Save method as shown below.

if(e != null && e.ImageFile != null) {
  //your action code goes here
  string filename = Path.GetFileNameWithoutExtension(e.ImageFile.FileName);
  //other code goes here

}