自己编写 EntityTypeConfiguration

1.新建类库 EFCore.EntityTypeConfig ，安装nuget  PM> Install-Package Microsoft.EntityFrameworkCore

2.新建接口IEntityTypeConfiguration

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
using System;
using System.Collections.Generic;
using System.Text;

namespace EFCore.EntityTypeConfig
{
  public  interface IEntityTypeConfiguration
    {
        void Map(ModelBuilder bulder);
    }
    public interface IEntityTypeConfiguration<T>:IEntityTypeConfiguration where T:class
    {
        void Map(EntityTypeBuilder<T> builder);
    }
}

新建类EntityTypeConfiguration.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
using System;
using System.Collections.Generic;
using System.Text;

namespace EFCore.EntityTypeConfig
{
   public abstract class EntityTypeConfiguration<T>:IEntityTypeConfiguration<T> where T:class
    {
        public abstract void Map(EntityTypeBuilder<T> builder);
        public void Map(ModelBuilder builder)
        {
            Map(builder.Entity<T>());
        }
    }
}

 新建类ModelBuilderExtenions.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;

namespace EFCore.EntityTypeConfig
{
    public static class ModelBuilderExtenions
    {
        private static IEnumerable<Type> GetMappingTypes(this Assembly assembly, Type mappingInterface) {
            return assembly.GetTypes().Where(x => !x.GetTypeInfo().IsAbstract
            && x.GetInterfaces().Any(y => y.GetTypeInfo().IsGenericType
            && y.GetGenericTypeDefinition() == mappingInterface)); }

        public static void AddEntityConfigurationsFromAssembly(this ModelBuilder modelBuilder, Assembly assembly)
        {
            var mappingTypes = assembly.GetMappingTypes(typeof(IEntityTypeConfiguration<>));
               foreach (var config in mappingTypes.Select(Activator.CreateInstance).Cast<IEntityTypeConfiguration>()) { config.Map(modelBuilder); }
        }
    }
}

3.控制台引用类库EFCore.EntityTypeConfig 

using EFCore.EntityTypeConfig;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text;

namespace ConsoleApp3
{
    public class MyDbContext:DbContext
    {
        public DbSet<Person> Persons { get; set; }
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            // modelBuilder.Entity<Person>().ToTable("T_Persons").Property(e => e.Id).IsRequired();
            // modelBuilder.Entity<Person>().ToTable("T_Persons") ;

            modelBuilder.AddEntityConfigurationsFromAssembly(Assembly.GetEntryAssembly());
        }
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            base.OnConfiguring(optionsBuilder);
            optionsBuilder.UseMySql("Server=127.0.0.1;database=test;uid=root;pwd=123321");
        }
    }
}