使用枚举列表时,MudInput总是显示第一个条目

发布于 2025-02-09 16:56:29 字数 1796 浏览 2 评论 0原文

我有一个使用枚举列表的MudSelect。不幸的是,它总是在输入字段中以值0显示枚举,即使它也不是所选值列表的一部分。同样,MultiSelectionTextFunc似乎无法正常工作,这意味着它隐藏在标记中。

<div class="mud-input mud-input-outlined ...">
<input class="mud-input-slot mud-input-root ..." type="**hidden**" readonly="" inputmode="text" maxlength="524288"
value="**None**">
<div class="mud-input-slot mud-input-root ..." style="display:inline" tabindex="0">**Cat**</div>

因此,如果是tenum,

enum Animal
{
    Cat,
    Tiger
}

它将始终在选择字段中显示“ CAT”,但是它应该显示“无”,如您在上面的标记中所看到的。

如何在MudSelect中正确使用枚举?

public HashSet<TEnum> Values { get; set; } = Enum.GetValues<TEnum>().ToHashSet();

public Dictionary<TEnum, string> Labels { get; set; } = new Dictionary<TEnum, string>();

private List<TEnum> SelectedValues { get; set; } = new List<TEnum>();

<MudSelect
    T="TEnum"
    Margin="Margin.Dense"
    Variant="Variant.Outlined"
    MultiSelection
    SelectedValues="SelectedValues"
    SelectedValuesChanged="SelectedValuesChanged"
                    
    MultiSelectionTextFunc="FilterMultiSelectionTextFunc"
    Label="@Frontend.Common_Filters">
    @foreach(var value in Values)
    {
        <MudSelectItem T="TEnum" Value="value">
            @value.ToString()
        </MudSelectItem>
    }
</MudSelect>


public void SelectedValuesChanged(IEnumerable<TEnum> selected)
{
    SelectedValues.Clear();
    SelectedValues.AddRange(selected);
}

private static string FilterMultiSelectionTextFunc(List<string> items)
{
    if (items.Count == 0)
    {
        return "None";
    }
    else if (items.Count == 1)
    {
        return items[0].ToString();
    }

    return $"{items.Count} selected";
}

I have a MudSelect which uses a list of Enums. Unfortunately it always displays the Enum with value 0 in the input field, even it is not part of the SelectedValues list. Also MultiSelectionTextFunc doesn't seem to work properly, meaning it is hidden in the markup.

<div class="mud-input mud-input-outlined ...">
<input class="mud-input-slot mud-input-root ..." type="**hidden**" readonly="" inputmode="text" maxlength="524288"
value="**None**">
<div class="mud-input-slot mud-input-root ..." style="display:inline" tabindex="0">**Cat**</div>

So if TEnum is

enum Animal
{
    Cat,
    Tiger
}

it will always display "Cat" in the select field, but it should display "None" as you can see in the markup above.

How can I use Enums correctly in MudSelect with MultiSelection?

public HashSet<TEnum> Values { get; set; } = Enum.GetValues<TEnum>().ToHashSet();

public Dictionary<TEnum, string> Labels { get; set; } = new Dictionary<TEnum, string>();

private List<TEnum> SelectedValues { get; set; } = new List<TEnum>();

<MudSelect
    T="TEnum"
    Margin="Margin.Dense"
    Variant="Variant.Outlined"
    MultiSelection
    SelectedValues="SelectedValues"
    SelectedValuesChanged="SelectedValuesChanged"
                    
    MultiSelectionTextFunc="FilterMultiSelectionTextFunc"
    Label="@Frontend.Common_Filters">
    @foreach(var value in Values)
    {
        <MudSelectItem T="TEnum" Value="value">
            @value.ToString()
        </MudSelectItem>
    }
</MudSelect>


public void SelectedValuesChanged(IEnumerable<TEnum> selected)
{
    SelectedValues.Clear();
    SelectedValues.AddRange(selected);
}

private static string FilterMultiSelectionTextFunc(List<string> items)
{
    if (items.Count == 0)
    {
        return "None";
    }
    else if (items.Count == 1)
    {
        return items[0].ToString();
    }

    return 
quot;{items.Count} selected";
}

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烏雲後面有陽光 2025-02-16 16:56:29

问题似乎是Tenum并非无效。如果选择值是单个值而不是列表,这对我来说是有意义的,因为默认值是0。我的空列表对我来说意味着没有选择的值。无论如何,可以通过将Tenum更改为Tenum来解决问题吗?如:

private List<TEnum?> SelectedValues { get; set; } = new List<TEnum?>();

<MudSelect
    T="TEnum?"
...>
    @foreach(var value in Values)
    {
        <MudSelectItem T="TEnum?" Value="value">
            @value.ToString()
        </MudSelectItem>
    }
</MudSelect>

The issue seems to be that TEnum is not nullable. This would make sense for me if the SelectedValues was a single value and not a list, since the default value then would be 0. An empty list for me means there is no value selected. Anyway the problem can be resolved by changing TEnum to TEnum? as in:

private List<TEnum?> SelectedValues { get; set; } = new List<TEnum?>();

<MudSelect
    T="TEnum?"
...>
    @foreach(var value in Values)
    {
        <MudSelectItem T="TEnum?" Value="value">
            @value.ToString()
        </MudSelectItem>
    }
</MudSelect>
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