Select box binding in blazor

Question

I am trying to bind CountryId in the model to the value of a selected item of SelectList in Blazor. All of the Country items come in a list like {CountryId, CountryName} object. I do the code like so:

    <InputSelect @bind-Value="model.ByCountryId" class="form-control">
        @if (model?.Countries != null)
        {
           @foreach (var cnt in model.Countries)
           {
               <option value="@cnt.Id">@cnt.Name</option>
           }
        }
     </InputSelect>

And code block:

@code {

BrandModel model = new BrandModel();

protected override async Task OnInitializedAsync()
{
    model = new BrandModel
    {
        Id = 19,
        ByCountryId = 1,
        Countries = new List<ent.Country>
            {
                new ent.Country { Id = 1, Name = "Azerbaijan" },
                new ent.Country { Id = 2, Name = "Turkey" }
            },
        IsActive = true,
        Name = "Brand"
    };
}

But this execution gives me this error in the browser:

blazor.webassembly.js:1 WASM: System.MissingMethodException: Constructor on type 'System.ComponentModel.ByteConverter' not found.

What is the convenient way of binding <select> and model.data in Blazor?

Solution 1

It works well when I put the <InputSelect> in a <EditForm Model="@model">..</EditForm >and there's no problem in your data binding.

Try to use below code to set <BlazorLinkOnBuild>false</BlazorLinkOnBuild> in the csproj file.

<PropertyGroup>
   <BlazorLinkOnBuild>false</BlazorLinkOnBuild>
</PropertyGroup>

Refer to https://github.com/aspnet/AspNetCore/issues/7784

Update:

Use <select> tag instead of <InputSelect> like

<select @bind="model.ByCountryId">
        @if (model?.Countries != null)
        {
            @foreach (var cnt in model.Countries)
            {
                <option value="@cnt.Id">@cnt.Name</option>
            }
        }
</select>

Solution 2

<InputSelect> works for me In .NET 5. For every Inputs (text, number, date, select, checkbox etc) I use <EditForm> with Model.

<EditForm Model="item">
   <InputSelect @bind-Value="item.CountryId">
      <option value=""></option>
      @foreach (var c in countries)
      {
         <option value="@c.Id">@c.Name</option>
      }
   </InputSelect>
</EditForm>

For this example: ItemModel item has at least property CountryId and List<CountryModel> countries has at least properties int Id and string Name