DataTypeAnnotations MetadataType 未按预期工作

Question

I try to implement Metadatatype, in order to seperate Validation attributes from my Acquisitiecode class, into the AcquisitiecodeAnnotations class.

Now when I add attributes (like Required, StringLength and so on) to the Acquisitiecode class, validation works as expected. When I move these attributes to the AcquisitiecodeAnnotations class and bind this class using the MetadataType attribute, I does not work.

Please find the code examples below (I've stripped them down for readability). Also, the project is an ASP.NET Core 3.0 web application. All code, including the examples are also running in.NET Core 3.0 projects.

Snippet 1:

using System;
using System.ComponentModel.DataAnnotations;

namespace Shared.Entities
{
    [MetadataType(typeof(AcquisitiecodeAnnotations))]
    public partial class Acquisitiecode
    { }

    public partial class AcquisitiecodeAnnotations
    {
        [StringLength(4, ErrorMessage = "The value cannot exceed 4 characters. ")]
        public string Acquisitiecode1 { get; set; }
    }
}

Snippet 2:

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace Shared.Entities
{
    public partial class Acquisitiecode
    {
        public Acquisitiecode()
        {
            Lidmaatschap = new HashSet<Lidmaatschap>();
        }

        public string Acquisitiecode1 { get; set; }

        public virtual Lid Lid { get; set; }
        public virtual ICollection<Lidmaatschap> Lidmaatschap { get; set; }
    }
}

Answer 1

As of October 2020 the current version of Blazor does not support Metadatatype . For more information please read this issue .