Hello everyone, am trying to pass a list of data in a form from a view to mvc controller. there is no model for it

Question

this is the view code

@{
ViewData["Title"] = "Result Table";
}

this is the controller code.

using GPA_CALCULATOR.Models; 
using Microsoft.AspNetCore.Mvc; using System.Diagnostics;
namespace GPA_CALCULATOR.Controllers 
{ 
    public class HomeController : Controller 
   { 
    private readonly ILogger _logger;
    public HomeController(ILogger logger)
    {
        _logger = logger;
    }
    public IActionResult Index()
    {
        return View();
    }
    public IActionResult Privacy()
    {
        return View();
    }
    [HttpPost]
    public IActionResult CalculateGpa()
    {
        var subjects = Request.Form["subjects"];
        var creditUnits =Request.Form["creditunits"];
        var gradePoint = Request.Form["gradepoints"];
       
        int totalCredits = 0;
        int totalGradePoints = 0;
        for (int i = 0; i < subjects.Count; i++)
        {
            
            int credit = int.Parse(creditUnits[i]);
            int grade = int.Parse(gradePoint[i]);
            
            totalCredits += credit;
            totalGradePoints += grade * credit;
        }
        int GpaCalculator = (int)totalGradePoints + totalCredits;
        
        ViewBag.GPA = GpaCalculator;
        return View("Privacy");
    }
    [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
    public IActionResult Error()
    {
        return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
    }
  }
}

Answer

the subjects name in the form is "subject" and the gradepoint name is "gradepoint". try:

        var subjects = Request.Form["subject"];
        var creditUnits =Request.Form["creditunits"];
        var gradePoint = Request.Form["gradepoint"];

Answer

trying to pass a list of data in a form from a view to mvc controller. there is no model for it

You cannot obtain a list of data in the way you did in your code, i.e.,:

var subjects = Request.Form["subjects"]; var creditUnits =Request.Form["creditunits"]; var gradePoint = Request.Form["gradepoints"];

I recommend that you define a view model such like:

Model

namespace MvcNet8App.Models
{
    public class Gpa
    {
        public string? Subject { get; set; }
        public string? Creditunit { get; set; }
        public string? GradePoint { get; set; }
    }
}

and use the view model in the controller to pass data between controller and view:

Controller

using Microsoft.AspNetCore.Mvc;
using MvcNet8App.Models;

namespace MvcNet8App.Controllers
{
    public class CollectionController : Controller
    {        
        public IActionResult Index()
        {
            return View();
        }
        
        public IActionResult CalculateGpa()
        {
            return View();
        }

        [HttpPost]
        [ValidateAntiForgeryToken]
        public IActionResult CalculateGpa(List gpa)
        {
            if (ModelState.IsValid)
            {
                return RedirectToAction(nameof(Index));
            }

            return View();
        }
    }    
}

View

Rewrite your view as shown below.

Please note:

Do not use readonly attribute for the input element because it does not post the value to controller.
Assign index to name attribute of input elements such like name="[0].subject".
Names of name attribute (i.e., subject, creditUnit and gradePoint shown below) must match with the property names of Gpa class. They are not case-sensitive.

@{
    ViewData["Title"] = "CalculateGpa";
}

CalculateGpa

Result

The following data,

enter image description here

are posted and properly passed to the argument of CalculateGpa(List gpa) as shown below:

enter image description here

Answer

This answer has been deleted because of duplication.

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Hello everyone, am trying to pass a list of data in a form from a view to mvc controller. there is no model for it

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