MudSelect选择选项后错误验证状态自动消失的问题求助

问题重现 #

使用MudBlazor v8.5.1的MudSelect组件，手动通过Error和ErrorText绑定控制错误提示：

<MudSelect @bind-Value="value" T="string" Label="Test Select" Error="@isInError" ErrorText="The field is in error">
    @foreach(string option in options)
    {
        <MudSelectItem T="string" Value="@option">@option</MudSelectItem>
    }
</MudSelect>

<MudButton ButtonType="ButtonType.Button" OnClick="@Validate">Validate</MudButton>

@code {
    private bool isInError = false;
    private string value = string.Empty;
    private List<string> options = ["opt1", "opt2", "opt3", "opt4"];
        
    private void Validate()
    {
        if (value == string.Empty)
        {
            isInError = true;
        }
    }
}

未选择选项时点击验证按钮，错误提示正常显示；但选择任意选项后，错误提示会自动消失，无法保持手动设置的错误状态，而同页面的MudTextField无此问题。

解决方案 #

MudSelect默认开启了*ResetErrorOnInput*参数（值为true），该参数会在用户选择选项时自动重置组件的错误状态。只需将此参数设置为false，即可阻止组件自动清除错误，仅通过手动修改isInError来控制错误状态：

<MudSelect @bind-Value="value" T="string" Label="Test Select" Error="@isInError" ErrorText="The field is in error" ResetErrorOnInput="false">
    @foreach(string option in options)
    {
        <MudSelectItem T="string" Value="@option">@option</MudSelectItem>
    }
</MudSelect>

<MudButton ButtonType="ButtonType.Button" OnClick="@Validate">Validate</MudButton>

@code {
    private bool isInError = false;
    private string value = string.Empty;
    private List<string> options = ["opt1", "opt2", "opt3", "opt4"];
        
    private void Validate()
    {
        // 可自定义任意验证逻辑，不局限于是否为空
        isInError = value == string.Empty || value == "opt2"; // 示例：选择opt2也标记错误
    }
}

复杂验证场景补充 #

如果需要统一管理表单验证逻辑，建议结合MudBlazor的EditForm和DataAnnotations体系，避免手动控制错误状态的繁琐：

<EditForm Model="@model" OnValidSubmit="@HandleValidSubmit">
    <DataAnnotationsValidator />
    <MudSelect @bind-Value="model.SelectedOption" T="string" Label="Test Select">
        @foreach(string option in options)
        {
            <MudSelectItem T="string" Value="@option">@option</MudSelectItem>
        }
    </MudSelect>
    <ValidationMessage For="@(() => model.SelectedOption)" />
    
    <MudButton ButtonType="ButtonType.Submit">Validate</MudButton>
</EditForm>

@code {
    private FormModel model = new();
    private List<string> options = ["opt1", "opt2", "opt3", "opt4"];
        
    private void HandleValidSubmit()
    {
        // 验证通过后的业务逻辑
    }
    
    public class FormModel
    {
        [Required(ErrorMessage = "必须选择一个选项")]
        [RegularExpression(@"^(?!opt2$).*$", ErrorMessage = "不能选择opt2")]
        public string SelectedOption { get; set; } = string.Empty;
    }
}

内容的提问来源于stack exchange，提问作者user21415940