使用IModelValidator创建自定义属性验证属性

using System;
using System.ComponentModel.DataAnnotations;
using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;

public class CustomValidationAttribute : ValidationAttribute
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        // 自定义属性值验证逻辑
        // 如果属性值有效，返回ValidationResult.Success
        // 如果属性值无效，返回一个包含错误信息的ValidationResult对象
    }
}

public class CustomModelValidator : IModelValidator
{
    public IEnumerable<ModelValidationResult> Validate(ModelValidationContext validationContext)
    {
        var propertyValidators = validationContext.ModelMetadata.ValidatorMetadata
            .OfType<CustomValidationAttribute>();

        foreach (var validator in propertyValidators)
        {
            var validationResult = validator.GetValidationResult(validationContext.Model);

            if (validationResult != ValidationResult.Success)
            {
                yield return new ModelValidationResult(
                    validationContext.ModelMetadata.PropertyName,
                    validationResult.ErrorMessage);
            }
        }
    }
}

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc()
            .AddMvcOptions(options =>
            {
                options.ModelValidatorProviders.Add(new CustomModelValidatorProvider());
            });
    }
}