C# ASP.NET views - passing data from a drop down into the view

Question

0.00/5 (No votes)

See more:

I am new to .Net Core and coding and I am making a web MVC app. Now its going great but I cant seem to get a drop down to work properly. I can the values in the view but when I post back to the controller to create a new part its not passing the Id. Id welcome some feedback on what I am doing wrong:

Controller

public IActionResult Create()
        {
            ViewBag._PartTypes = new SelectList(partType.ReturnAllPartTypes(), "Id",   "PartTypeName");
            
            return View();
        }

<div class="form-group">
    @Html.LabelFor(x => x.PartTypeId)
    @Html.DropDownListFor(model => model.PartTypeId, (IEnumerable<SelectListItem>)ViewBag._PartTypes)
</div>

What I have tried:

Ive tried different variations of the fields and different approaches and I am just stumped.

Posted 10-Jul-20 23:26pm

RabsoInc

Updated 11-Jul-20 8:13am

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Dave Kreskowiak · Accepted Answer · 2020-07-11T08:13:00

Your model is empty because you didn't pass anything to the View. Note there is nothing inside the parenthesis:

C#

return View();

So, since you didn't pass anything to the view, your references to "model" in the Razor code will all be null:

C#

@Html.DropDownListFor(model => model.PartTypeId, (IEnumerable<SelectListItem>)ViewBag._PartTypes)

Don't use the ViewBag if you're using MVC. It's just going to confuse you.

The purpose of the Model is to pass any data to the view that renders the HTML any data it needs to build the HTML, including the contents of DropDownList's.