更新实体数据模型时，如何在不更改的情况下继续在类中使用 System.ComponentModel.DataAnnotations？

Question

How can I update Model from Database and keep my models DataAnnotations without change ?

Always after update model from database I need to add

using System.ComponentModel.DataAnnotations; 

again for each class and add

[Display(Name = "Name")]

for all fields and this take long time with every single update

How can I skip this step and update model from database and keep that settings ?

Answer 1

Use the MetadataTypeAttribute class to achieve the solution you are looking for.

The documentation contains detailed description how to use is.

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As an example, let say you have an entity class Order with the following properties:

public class Order
{
    public int OrderId { get; set; }
    public string OrderDescription { get; set; }
    public string BillingAddress { get; set; }
    … // another properties
}

The solution is to add partial declaration to the model class and to create a second partial class that contains the metadata:

using System;
using System.ComponentModel.DataAnnotations;

[MetadataType(typeof(OrderMetaData))]
public partial class Order
{
    public int OrderId { get; set; }
    public string OrderDescription { get; set; }
    public string BillingAddress { get; set; }
    … // another properties
}

Creating a meta data class with required annotations:

using System;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Web.Mvc;

public partial class OrderMetaData 
{
    [HiddenInput(DisplayValue=false)]
    public int OrderId { get; set; }
    
    [Display(Name="Description")]
    public string OrderDescription { get; set; }
    
    [Display(Name = "Billing Address")]
    public string BillingAddress { get; set; }
}

The meta data class only needs to contain properties that you want to apply annotations. Take care the entity class and the meta data class have consistent namespaces.