HTTP 400 When Too Many Form Items

Question

I have an Asp.Net Core 5 Razor Pages. There's a Razor page with a form that the user uses to edit invoices. When the number of items in the form increases substantially (around 500 items) the application returns an HTTP 400 error. Here's the summary of how I handle items and the form:

Page Model

[DisableRequestSizeLimit]
public class EditModel : PageModel
{
    [BindProperty]
    public OrderCreateViewModel Input { get; set; }
    
    //...rest of the code
}

ViewModel

public class OrderCreateViewModel
{
    public int Id { get; set; }
    public int CustomerId { get; set; }
    public string ReceiverName { get; set; }
    public string Address { get; set; }
    public string PostalCode { get; set; }
    public string Phone { get; set; }
    public string DeliveryDate { get; set; }
    public string CustomerName { get; set; }
    //... other fields

    public int[] ItemIds { get; set; }
    public decimal[] Quantities { get; set; }
    public decimal[] Fees { get; set; }
    public decimal[] Discounts { get; set; }
    public decimal[] Taxes { get; set; }
    public decimal[] Duties { get; set; }
    public string[] ItemComments { get; set; }
    public decimal[] Max { get; set; }
}

Razor

<form method="post" enctype="multipart/form-data">
    <input type="hidden" asp-for="Input.Id" />
    <label asp-for="Input.CustomerName"></label>
    <input asp-for="Input.CustomerName" disabled class="form-control" />
    ...

    <table class="table mt-5 w-100 table-bordered table-responsive" id="quotation-items">
        <thead>
            <tr>
                <td>Quantity</td>
                <td>Fee</td>
                ... rest of items...
            </tr>
        </thead>
        <tbody>
            @for (int i = 0; i < Model.Input.ItemIds.Length; i++)
            {
                <tr>
                    <td>
                        <input type="text" name="Input.Quantities[]" value="@Model.Input.Quantities[i].ToString("0.##")" />
                    </td>
                    <td>
                        <input type="text" name="Input.Fees[]" value="@Model.Input.Fees[i].ToString("0.##")" />
                    </td>
                    ... rest of items ...
                </tr>
            }
        </tbody>
    </table>

    <button class="btn btn-primary btn-lg" id="btn-submit">
        Save
    </button>
</form>

How can this be fixed? I already added the [DisableRequestSizeLimit] attribute to the page model but it didn't work. I also tried increasing the limit by changing the web.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<system.web>
        <httpRuntime maxRequestLength="500000000"  executionTimeout="120" />
    </system.web>
  <location path="." inheritInChildApplications="false">
    <system.webServer>
      <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
      </handlers>
      <aspNetCore processPath=".\Project.exe" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
<security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="1073741824" />
      </requestFiltering>
    </security>
    </system.webServer>
  </location>
</configuration>

Edit1:

I did some debugging. For some reason the form works if the number of items are exactly 144 items. I tried with different items.

Answer 1

Please add this to Startup#ConfigureServices

services.Configure<FormOptions>(options => options.ValueCountLimit = 5000);

This will increase your limit to 5000.