How get List<~> fron View to Controller MVC

Question

I have three related tables

In the table "SelectedMaterial" need to enter the values in the column "CountMaterial" (initially there null)

For this in controller I have POST and GET methods

public ActionResult EditCountOfMaterial(int id)
    {
        var selectedmaterial = db.SelectedMaterials.Where(m => m.CardId == id).ToList();
        return View(selectedmaterial);
    }

    [HttpPost]
    public ActionResult EditCountOfMaterial(List<SelectedMaterial> material)
    {
        //material = db.SelectedMaterials.Where(m => m.CardId == 3).ToList();

        for (int i = 0; i < material.Count; i++)
        {
            //material[i] = db.SelectedMaterials.Where(m => m.CardId == 3).First();
            db.Entry(material[i]).State = EntityState.Modified;               
            db.SaveChanges();
        }
        return RedirectToAction("Index");
    }

I also have a view

@model IEnumerable<AccountingPlusProject.Models.SelectedMaterial>
@{
ViewBag.Title = "EditCountOfMaterial";
}

<h2>EditCountOfMaterial</h2>
@using (Html.BeginForm())
{
foreach (var item in Model)
{
    @item.ReferenceMaterial.NameMaterial
    <div class="form-group">
        @Html.LabelFor(model => item.CountMaterial, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => item.CountMaterial, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => item.CountMaterial, "", new { @class = "text-danger" })
        </div>
    </div>
}
<div class="form-group">
    <div class="col-md-offset-2 col-md-10">
        <input type="submit" value="Save" class="btn btn-default" />
    </div>
</div>
}

But from the view comes null values. How to pass list from View with a value?

Could you give an example in the view with loop? Because the number of SelectedMaterial depends on the TechCard. What is my solution not correct? — nlipatov, Dec 12 '16 at 19:18

Scott Dobbins · Answer 1 · 2016-12-12T20:12:39.377

0

Something like Below. The Posted back values have to be in array form.

  @using (Html.BeginForm())
  {
    foreach (var item in Model)
    {
     var count= 0;
     @item.ReferenceMaterial.NameMaterial
     <div class="form-group">
        @Html.LabelFor(model => item.CountMaterial, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
              @Html.EditorFor(model => item.CountMaterial, new { htmlAttributes = new { @class = "form-control", @name="SelectedMaterial[" + count.ToString() + "].CountMaterial"} })
              @Html.ValidationMessageFor(model => item.CountMaterial, "", new { @class = "text-danger" })
         </div>
      </div>
     count+=1;
     }

   }

edited Dec 12 '16 at 20:12

answered Dec 12 '16 at 19:24

Scott Dobbins

294
1
8

Sorry for such a stupid question, but how in this case to use a button to send the data? – nlipatov Dec 12 '16 at 19:42
The button you have in the above example would work fine. Any input button with type of 'Submit' will post the form data back. You just have to name it correctly for MVC to bind it correctly to the expected Model in your controller – Scott Dobbins Dec 12 '16 at 19:45
errors with the count, if use @using (Html.BeginForm()) – nlipatov Dec 12 '16 at 19:48
if remove the @using (Html.BeginForm ()) then stops working – nlipatov Dec 12 '16 at 19:50
replace count+=1; with @{count+=1;} – Scott Dobbins Dec 12 '16 at 19:54
error in this line with "count" - @Html.EditorFor(model => item.CountMaterial, new { htmlAttributes = new { @class = "form-control", name = "SelectedMaterial[" + count.ToString() + "].CountMaterial}" } }) and in this line - { count += 1;} – nlipatov Dec 12 '16 at 20:03
Hold on...Let me edit in a project and Ill post the update above. – Scott Dobbins Dec 12 '16 at 20:05
How can I send you my project? – nlipatov Dec 12 '16 at 20:10
The Above should work now. Was missing a quote – Scott Dobbins Dec 12 '16 at 20:13
After the fix still passes null in the POST: System.NullReferenceException:for (int i = 0; i < material.Count; i++) { – nlipatov Dec 12 '16 at 20:22
change your variable name in the controller from material to SelectedMaterial and see if that fixes it – Scott Dobbins Dec 12 '16 at 20:26
need to change the input parameter? – nlipatov Dec 12 '16 at 20:30
I changed the name, but debug still in the beginning of the loop shows null – nlipatov Dec 12 '16 at 20:45
Can you run fiddler, etc and see what values are being posted back? – Scott Dobbins Dec 12 '16 at 20:49
be sure your Class SelectedMaterial has an empty Constructor defined also – Scott Dobbins Dec 12 '16 at 20:50
Class SelectedMaterial namespace AccountingPlusProject.Models { using System; using System.Collections.Generic; public partial class SelectedMaterial { public int CardId { get; set; } public int MaterialId { get; set; } public Nullable CountMaterial { get; set; } public virtual ReferenceMaterial ReferenceMaterial { get; set; } public virtual TechnologicalCard TechnologicalCard { get; set; } } } – nlipatov Dec 12 '16 at 20:59
You need to add an empty constructor Public SelectedMaterial(){} – Scott Dobbins Dec 12 '16 at 21:01
I added a constructor, but the error is the same( – nlipatov Dec 12 '16 at 21:04

How get List<~> fron View to Controller MVC

1 Answers1