Asp.net Core Razor persist data in a view over reload

Question

In my Razor app I can add in the details below and return the Result in a list, as well as area and cost. How do I persist that list of Results so it saves multiple results?

I am posting the results as

<form method="post"> 

and using the carpet class as

    [BindProperty(SupportsGet = true)]
    public Carpet? carpet { get; set; }

My OnPostAsync is

public async Task<IActionResult> OnPostAsync()
    {
        if (ModelState.IsValid)
        {
some code....
carpet.FinalCost = carpetOperations.TotalInstallCost(carpet);
carpet.Results.Add("Room area " + carpet.RoomArea + "sqm $" + carpet.FinalCost);
        }
        return Page();
    }

But I want to persist the data in my carpet.Results List across different entries.

I have also tried it as a Property

  public List<string> CarpetResults { get; set; }

and instantiated it in the constructor

 public IndexModel(ILogger<IndexModel> logger)
    {
        _logger = logger;

        CarpetResults = new List<string>();
    }

But it still resets after every page load.

Answer 1

For anyone wondering the same I found a solution without using a db. I am making a small app that is not public facing and only as a teaching tool, so security is not so much an issue, and I didn't want a db.

So I created a static class, and just used that.

  public static class StaticList
{
    public static List<string>? StaticStudentResults { get; set; } = new 
 List<string>();
} 

And in my codebehind I just passed the data to the same list structure held on the page

StudentResults.AddRange(StaticList.StaticStudentResults);

Naturally this could be a huge security hole and do not recommend it for public facing sites.