Object reference not set to an instance of an object MVC - html

Question

this is my models:
public class Ressource
{
[Key]
public int RessourceId { get; set; }
public string TitreR { get; set; }
public string Link { get; set; }
public string Type { get; set; }
public string Desc { get; set; }
public int Position { get; set; }
public int Rating { get; set; }
public string Tags { get; set; }
public int SectionId { get; set; }
public int UserId { get; set; }
}
public class Section
{
[Key]
public int SectionId { get; set; }
public string Titre { get; set; }
public String Tags { get; set; }
public virtual ICollection<Ressource> Ressources { get; set; }
}
public class structure
{
public Ressource ress;
public List<string> liste;
}
In this view, I enter the resource's title (TitreR), a description (Desc) and I choose from a list of tags which ones I want to link with this resource as well as entering a tag:
#model Mocodis.Models.structure
#{
ViewBag.Title = "AjouterRessource";
}
<h2>AjouterRessource</h2>
#using (Html.BeginForm("AjouterRessource", "Home", FormMethod.Post))
{
#Html.AntiForgeryToken()
#Html.ValidationSummary(true)
<fieldset>
<input type="hidden" name="SectionId" value="#Model.ress.SectionId" />
<legend>Ressource</legend>
<div class="editor-label">
#Html.LabelFor(model => model.ress.TitreR)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.ress.TitreR)
#Html.ValidationMessageFor(model => model.ress.TitreR)
</div>
<div class="editor-label">
#Html.LabelFor(model => model.ress.Desc)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.ress.Desc)
#Html.ValidationMessageFor(model => model.ress.Desc)
</div>
</fieldset>
}
<form id="orderProductForm219" name="orderProductForm219" method="post" >
<b>Choisir les mots clés:</b>
<br /><br />
#foreach (string s in #Model.liste)
{
<input type="checkbox" name="tags[]" value="#s"> #s<br />
}
<input type="text" name="tags" id="tags" value="" />
<p>
<input type="submit" value="Create" />
<input type="hidden" name="tag" value="tags" />
<input type="hidden" name="res" value="#Model.ress" />
</p></form>
(I didnt put the javascript for it)
Finally the controllers are:
public ActionResult AjouterRessource(int SectionId)
{
Ressource res = new Ressource();
res.SectionId = SectionId;
Section sec = _db.Sections.Where(r => r.SectionId == SectionId).FirstOrDefault();
char[] delimiterChars = { ' ', ',', '.', ':', '\t' };
List<string> l = new List<string>();
l = sec.Tags.Split(delimiterChars).ToList();
structure s = new structure();
s.ress = res;
s.liste = l;
return View(s);
}
public string Check ( string list, string s)
{
char[] delimiterChars = { ' ', ',', '.', ':', '\t' };
List<string> l = new List<string>();
List<string> liste = new List<string>();
l = s.Split(delimiterChars).ToList();
liste = list.Split(delimiterChars).ToList();
foreach (string item in l)
{
if (!liste.Contains(item))
liste.Add(item);
}
return (string.Join(" ", liste.ToArray()));
}
[Authorize]
[HttpPost]
[InitializeSimpleMembership]
public ActionResult AjouterRessource(Ressource res, int SectionId, string tag)
{
if (ModelState.IsValid)
{
res.SectionId = SectionId;
var model = _db.Sections.Where(c => c.SectionId == SectionId).FirstOrDefault();
res.Tags = tag;
model.Tags = Check(model.Tags, tag);
_db.Entry(model).State = EntityState.Modified;
_db.Entry(res).State = EntityState.Added;
_db.SaveChanges();
return RedirectToAction("Section", new { SectionId = SectionId });
}
return View();
}
I keep getting: Object reference not set to an instance of an object on the line: #Html.ValidationSummary(true) in my view. Can you tell me how to fix it please?
Thank you

Answer 1

Every time I have gotten that error it has been from not initializing something. Looking through your code the only spot I am seeing that might need it is when you are setting structure. You might try putting a constructor on that class to initialize the fields and see if that helps. something like
public structure()
{
ress = new Resource();
liste = new List<string>();
}
You probably need to add the { get; set; } to the resource and list under structure as well. Hopefully this helps.