如何保持属性属性插入到ASP.NET MVC中自动生成的文件中

Question

I use ASP.NET MVC 5 and Entity Framework 6. So I have generated some files under *.tt

I would like to keep attributes that i inserted into those files because I have created many pages automatically based on Entity Framework classes.

But when I update Entity Framework model from the database I loose everything that I inserted.

So my question is how to keep it from deleting?

//------------------------------------------------------------------------------ // // This code was generated from a template. // // Manual changes to this file may cause unexpected behavior in your application. // Manual changes to this file will be overwritten if the code is regenerated. // //------------------------------------------------------------------------------

namespace MyWebSIte.DataModel
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;

    public partial class ItemMovement
    {
        public System.Guid ID { get; set; }

        [DataType(DataType.DateTime)]  <---- I would like to keep it.
        [DisplayFormat(DataFormatString = "{0:dd/MM/yyyy}", ApplyFormatInEditMode = true)]
        [Display(Name = "Fecha")]
        public System.DateTime? Changed { get; set; }

Answer 1

Those files are not meant to be edited manually. You should take advantage of the fact that those classes are partial and can be "extended". Take a look at Metadata classes , they will allow you to annotate properties.

Answer 2

The generated class ItemMovement is a partial class.
This allows you to write a second partial class which is marked with the necessary data annotations.
In your case the partial class ItemMovement would look like this:

   namespace MyWebSIte.DataModel
    {
        using System;
        using System.Collections.Generic;
        using System.ComponentModel;
        using System.ComponentModel.DataAnnotations;

        [MetadataType(typeof(ItemMovementMetaData))]
        public partial class ItemMovement
        {
            public System.Guid ID { get; set; }        
            public System.DateTime? Changed { get; set; }
        }

        public partial class ItemMovementMetaData {

            [DataType(DataType.DateTime)]
            [DisplayFormat(DataFormatString = "{0:dd/MM/yyyy}", ApplyFormatInEditMode = true)]
            [Display(Name = "Fecha")]
            public System.DateTime? Changed { get; set; }   

            //....................
        }
    }

Answer 3

You can use the codefirst which gives u max control over your models and dbcontext.

Step1 : Create a codefirst model using the existing database. codefirst model using the existing database

Step 2: now type enable-migrations in the package manager console

Step 3: You use the (db)context and the model generated from the database table. make changes to your model

Step 4: type add-migration [some name to identify the migration] in the package manager console

Step 5: check the generated migration file.

Step 6: type update-database in the package manager console

Now your changes are updated to the database. From now on you can us the codefirst approach to handle the changes to your database.