ASP.NET核心MetaDataType属性不工作

Question

我在域模型类上使用MetaDataType属性。它应该将属性信息从引用的类移动到已设置MetadataType属性的类中。但它不像广告上所说的那样。是什么引起了这个问题？

[MetadataType(typeof(ComponentModelMetaData))]
public partial class Component
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<Repo> Repos { get; set; }
    public string Description { get; set; }   
}


public class ComponentModelMetaData
{
    [Required(ErrorMessage = "Name is required.")]
    [StringLength(30, MinimumLength = 3, ErrorMessage = "Name length should be more than 3 symbols.")]
    public string Name { get; set; }
    public ICollection<Repo> Repos { get; set; }
    [Required(ErrorMessage = "Description is required.")]
    public string Description { get; set; }        
}

Answer 1

ASP.NET核心用途

Microsoft.AspNetCore.Mvc **ModelMetadataType** 

而不是

System.ComponentModel.DataAnnotations.**MetadataType** 

来源

尝试将属性更改为[ModelMetadataType(typeof(ComponentModelMetaData))]

Answer 2

实体类：

namespace CoreProject.Persistence.EFCore
{
    public partial class User
    {
        public User()
        {
            Reader = new HashSet<Reader>();
            Writer = new HashSet<Writer>();
        }

        public int UserId { get; set; }
        public string Email { get; set; }
        public string Password { get; set; }
        public string PasswordHashKey { get; set; }
        public byte Role { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public DateTime CreatedUtc { get; set; }
        public DateTime LastUpdateUtc { get; set; }
        public byte Status { get; set; }
        public bool Deleted { get; set; }
        public DateTime? ActivatedUtc { get; set; }
        public bool Test { get; set; }

        public virtual ICollection<Reader> Reader { get; set; }
        public virtual ICollection<Writer> Writer { get; set; }
    }
}

元数据(都必须使用相同的命名空间)：

namespace CoreProject.Persistence.EFCore
{
    [ModelMetadataType(typeof(IUserMetadata))]
    public partial class User : IUserMetadata
    {
        public string FullName => FirstName + " " + LastName;
    }

    public interface IUserMetadata
    {
        [JsonProperty(PropertyName = "Id")]
        int UserId { get; set; }

        [JsonIgnore]
        string Password { get; set; }
        [JsonIgnore]
        string PasswordHashKey { get; set; }
        [JsonIgnore]
        byte Role { get; set; }
    }
}

Answer 3

另一种方式..。使用相同的命名空间

public class ApirolesMetaData
{
    [Required]
    public string Name { get; set; }
}


[ModelMetadataType(typeof(ApirolesMetaData))]
public partial class Apiroles
{

}