ASP.NET Core使用EntityFrameworkCore CodeFrist

1,安装环境：

如果是VS2015，确保已经升级至 update3或以上

.net core sdk (https://www.microsoft.com/net/download/core)

vs2015 tools

2,创建一个asp.net Core的项目

3,创建实体Entity,用户和角色

    public class User
    {
        public int Id { get; set; }
        /// <summary>
        /// 角色Id
        /// </summary>
        public int RoleId { get; set; }
        public virtual Role Role { get; set; }
        /// <summary>
        /// 状态
        /// </summary>
        public int Status { get; set; }
        /// <summary>
        /// 登陆名
        /// </summary>
        public string Login { get; set; }
        /// <summary>
        /// 登陆密码
        /// </summary>
        public string Pwd { get; set; }
    }

    public class Role
    {
        public int Id { get; set; }
        /// <summary>
        /// 角色名
        /// </summary>
        public string Name { get; set; }
        /// <summary>
        /// 一个角色的多个用户
        /// </summary>
        public virtual ICollection<User> Users { get; set; }
    }

4，创建DbContext

    public class EFDbContext: DbContext
    {
        public EFDbContext(DbContextOptions<EFDbContext> options) : base(options)
        { }
        public DbSet<Role> Roles { get; set; }
        public DbSet<User> Users { get; set; }
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            Role(modelBuilder);
            User(modelBuilder);
        }

        private void User(ModelBuilder modelBuilder)
        {
            var userBuilder = modelBuilder.Entity<User>().ToTable("User");
            // Properties
            userBuilder.Property(t => t.Id).ValueGeneratedOnAdd();
            userBuilder.Property(t => t.RoleId).IsRequired();
            userBuilder.Property(t => t.Status).IsRequired();
            userBuilder.Property(t => t.Login).IsRequired().HasMaxLength(30);
            userBuilder.Property(t => t.Pwd).IsRequired().HasMaxLength(60);
            // Primary Key
            userBuilder.HasKey(t => t.Id);
            // Index
            userBuilder.HasIndex(t => t.Login);
            // Relationships
            userBuilder.HasOne(t => t.Role).WithMany(t => t.Users).HasForeignKey(t => t.RoleId);
        }

        private void Role(ModelBuilder modelBuilder)
        {
            var roleBuilder = modelBuilder.Entity<Role>().ToTable("Role");
            // Properties
            roleBuilder.Property(t => t.Id).ValueGeneratedOnAdd();
            roleBuilder.Property(t => t.Name).IsRequired().HasMaxLength(30);
            // Primary Key
            roleBuilder.HasKey(t => t.Id);
        }
    }

5，创建DbInitializer，用于创建初始数据

    public class DbInitializer
    {
        public async static Task InitData(EFDbContext context)
        {
            if (context.Database != null && context.Database.EnsureCreated())
            {
                //角色配置
                context.Roles.AddRange(new Role[]
                {
                    new Role { Name="超级管理员" },
                    new Role { Name="管理员" }
                });
                //默认用户
                context.Users.AddRange(new User[]
                {
                    new User { RoleId=1, Login="administrator", Pwd="111111" },
                    new User { RoleId=2, Login="admin", Pwd="111111" }
                });

                await context.SaveChangesAsync();
            }
        }

6，修改Startup类方法

在ConfigureServices添加如下代码

// DbContext
services.AddDbContext<EFDbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

在Configure方法内添加

        public async void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            app.UseMvc();

            await DbInitializer.InitData(app.ApplicationServices.GetService<EFDbContext>());
        }

7，修改appsettings.json

{
  "ConnectionStrings": {
    "DefaultConnection": "Data Source=.;Initial Catalog=LniceCore;Integrated Security=SSPI;"
  },
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  }
}

8，运行程序，查看结果