CODEWITHSUNDEEP
c#asp.netasp.net-mvcasp.net-core
Daniel Hill
Daniel Hill

Reputation: 71

ASP.NET Core - Passing Form data to Controller, then redirect

I currently am trying to build a "Index" form which has two submit boxes, and then when you hit submit, it adds the two numbers together and then displays the result.

I tried this without a Model (Using ViewData) and managed to get it working, but I'd like it to work with a model. I have attempted this a magnitude of ways but I just cannot see what I am missing.

Journey Class - Two string values and a value (this will be int once I get it working)

    public class JourneyCalculator
    {
        public string PostCodeOne { get; set; }
        public string PostCodeTwo { get; set; }
        public string DistanceValue { get; set; }
    }

Then my controller which has two actions, one standard Index form and one that is supposed to Calculate the mileage. With this I've tried the following:

  1. Passing the Model as below
  2. Trying to pass string values from the form (This just fails)
  3. Just simply returning View(model)
public class MapsController : Controller
    {
        public IActionResult Index(JourneyCalculator journeyCalculator)
        {
            return View(journeyCalculator);
        }

        [HttpPost]
        public IActionResult CalculateMileage(JourneyCalculator model)
        {
            model.DistanceValue = model.PostCodeOne + model.PostCodeTwo;
            return RedirectToAction("Index",model);
        }
    }

My form which I would hope passes PostCodeOne and PostCodeTwo to the "CalculateMileage" action. And then we update that value and then the Model.DistanceValue displays

<form>
    <div class="form-row">
        <div class="form-group col-md-6">
            <label>Postcode One</label>
            <input type="text" class="form-control" asp-for="PostCodeOne" placeholder="Postcode One">
        </div>
        <div class="form-group col-md-6">
            <label>Postcode Two</label>
            <input type="text" class="form-control" asp-for="PostCodeTwo" placeholder="Postcode Two">
        </div>
    </div>
    <button type="submit" class="btn btn-primary" asp-controller="Maps" asp-action="CalculateMileage">Calculate Mileage</button>
</form>

@if(Model != null)
{
    <h2>@Model.DistanceValue</h2>
}

I feel I am missing something really obvious, so any help would be fantastic!

When I hit "Submit" the URL updates to https://localhost:44301/Maps/CalculateMileage?PostCodeOne=123&PostCodeTwo=123 or https://localhost:44301/Maps/Index?PostCodeOne=123&PostCodeTwo=123 and both are failing, but I want to just pass the values to the CalculateMileage.

Thank you,

Upvotes: 1

Views: 2314

Answers (1)

haldo
haldo

Reputation: 16701

Don't redirect to the Index action, but return the Index view straight from the CalculateMileage action passing the model: return View("Index", model);

// controller
[HttpPost]
public IActionResult CalculateMileage(JourneyCalculator model)
{
    model.DistanceValue = model.PostCodeOne + model.PostCodeTwo;
    return View("Index", model);
}

I would also prefer to put the action/method on the form rather than the button:

<form asp-controller="Maps" asp-action="CalculateMileage" method="post">
    <div class="form-row">
    ...
</form>

Alternatively, add a method to handle POST requests on the Index action:

[HttpPost]
public IActionResult Index(JourneyCalculator model)
{
    model.DistanceValue = model.PostCodeOne + model.PostCodeTwo;
    return View(model);
}

Upvotes: 2

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