MudSelect rerenders content every time, resulting in bad performance

Bug type

Component

Component name

MudSelect

What happened?

I would like to make a country selector for a registration form using MudSelect. I have a countries.json with all country names, iso codes and flag base64 images.

I m rendering the dropdown with this code: <MudSelect Label="Country" Variant="Variant.Text" OffsetY="true" @bind-Value="registrationRequestDto.CountryAlpha3Code" For="@(() => registrationRequestDto.CountryAlpha3Code)"> @foreach (var country in countries) { <MudSelectItem Value="country.IsoAlpha3"> @* <img src="data:image/png;base64,@country.Flag" height="14" class="mr-2" />*@ @country.Name </MudSelectItem> } </MudSelect>

I have commented out the flag image part, and set them all to null, but the dropdown is still very slow.

Every time I open the dropdown or close it (either by clicking on an element, or clicking outside the dropdown) the foreach runs, and it creates 200+ MudSelectItems. This results in the UI totally freezing up for 1 second.

Expected behavior

I expected it to create the listitems once, and use it whenever I open the dropdown.

This might be a general Blazor issue \ question, but I think I have the best chance for help here.

Reproduction link

https://try.mudblazor.com/snippet/wOQFlucQyPhgdvTA

Reproduction steps

1. Click on dropdown
2. Notice the 1second delay

Relevant log output

No response

Version (bug)

5.1.5

Version (working)

No response

What browsers are you seeing the problem on?

Chrome

On what operating system are you experiencing the issue?

Windows

Pull Request

• I would like to do a Pull Request

Code of Conduct

• I agree to follow this project’s Code of Conduct