如何使用 MultiSelection="true" 使默认值出现在 MudBlazor MudSelect 中？

Question

我正在使用 MudBlazor 创建一个组件以 select MudSelect 中的多个项目。当我预填充值时，它们不会出现在 select 控件中。当控件展开时，正确的项目将显示为 selected。如果我修改 selection，它们就会显示出来。如果我不做任何更改就关闭扩展，他们不会。

我需要它们在初始状态下显示。

视频：https://share.clickup.com/clip/p/t1280802/25e76e23-189d-4696-a795-8640b31a798f/screen-recording-2021-03-30-09%3A52.webm

我这里有一个代码演示：https://try.mudblazor.com/snippet/mEmPkHHkpwkPNrkt

__Main.razor:

@using BlazorRepl.UserComponents

<MyComponent Config="MyLocations" 
    OnConfigChanged="LocationsChanged"></MyComponent>

@code {
    private List<Location> MyLocations;
    private List<Location> ModifiedLocations;

    protected override async Task OnInitializedAsync()
    {
        await base.OnInitializedAsync();
        MyLocations = new List<Location>() {Location.inside, Location.underwater};
    }

    private void LocationsChanged(List<Location> val)
    {
        ModifiedLocations = val;
    }
}

MyComponent.razor:

@using BlazorRepl.UserComponents

<MudPaper Elevation="3">
    <MudSelect Label="Locations" SelectedValues="new HashSet<Location>(Config)"
        T="Location" MultiSelection="true" >
        @foreach (Location val in Enum.GetValues(typeof(Location)))
        {
            <MudSelectItem Value="val" />
        }
    </MudSelect>
</MudPaper>

@code {
    [Parameter] public List<Location> Config {get; set;}
    [Parameter] public EventCallback<List<Location>> OnConfigChanged {get; set;}

    private void SelectedValuesChanged(HashSet<Location> val) {
        var v = new List<Location>(val);
        if (!Utilities.EnumListEquals(v, Config))
        {
            Config = v;
            OnConfigChanged.InvokeAsync(Config);
        }        
    }
}

stuff.cs:

namespace BlazorRepl.UserComponents
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    public static class Utilities {
        public static bool EnumListEquals<T>(List<T> one, List<T> two) where T : struct, IConvertible
        {
            if (!typeof(T).IsEnum)
            {
                throw new ArgumentException("T must be an enumerated type");
            }
            return (one.Count() == two.Count() &&
                    one.Count(two.Contains) == two.Count());
        }
    }

    public enum Location { inside, outside, underwater }
}

Answer 1

这是 MudBlazor 中的错误。将在下一版本 MudBlazor v5.0.8

中修复

如何使用 MultiSelection="true" 使默认值出现在 MudBlazor MudSelect 中？

How do I get default values to appear in MudBlazor MudSelect with MultiSelection="true"?

c#

blazor

asp.net-core-3.1

mudblazor