.NET 7.0 EF Core：一、创建Web API 项目基础框架和用户表的增删改查

demo 地址: https://github.com/iotjin/Jh.Admin.NETCore
代码不定时更新，请前往github查看最新代码

官方教程

EF Core 官方文档
官方文档: 教程：使用 ASP.NET Core 创建最小 API
EFCore 查询数据
第一个EFCore应用
使用 NuGet 包管理器在 Visual Studio 中安装和管理包
常见的数据库提供程序

NuGet 包网站

序

本文记录如何使用 MySQL+ .NET 7 + Entity Framework Core (EF Core) + Code First + Fluent API 搭建一个后台管理系统框架。项目采用常见的分层结构，适合后续扩展用户、角色、菜单管理等模块。

• Admin.NETCore.API：接口入口层（API 层），Web API 入口
• Admin.NETCore.Core：核心业务层，Interface、Service、ViewModel、DTO等
• Admin.NETCore.Infrastructure：基础设施层，数据库、Fluent API配置、Entity、Migrations等
• Admin.NETCore.Common：通用功能层，工具类等

一、项目目录结构

Admin.NETCore
├── Admin.NETCore.API // 接口入口层
├── Admin.NETCore.Core // 核心业务层
├── Admin.NETCore.Infrastructure // 基础设施层
└── Admin.NETCore.Common // 通用功能层

---

各层职责说明

1️⃣ Admin.NETCore.API（接口层）

负责处理 HTTP 请求和响应，是整个项目的对外入口。

主要目录：

• Controllers/：控制器，如 UserController、RoleController
• Identity/Filters/：请求验证过滤器，如 ValidationFilter.cs
• ServiceExtensions/：服务注册扩展类（中间件、Swagger、CORS 等）
• Program.cs：程序主入口
• appsettings.json：配置文件

---

2️⃣ Admin.NETCore.Core（核心业务层）

包含系统的业务逻辑、接口定义、DTO/ViewModel，不依赖基础设施层。

主要目录：

• Interfaces/：接口定义，如 IUserService、IRoleService
• Services/：核心业务逻辑的实现
• ViewModels/：DTO/ViewModel 传输模型，分为 UserDTO, RoleDTO, UserVModel 等

---

3️⃣ Admin.NETCore.Infrastructure（基础设施层）

实现所有对数据库的访问逻辑，包含 EF Core 实体、配置和上下文等。

主要目录：

• Entities/：实体类，如 User, Role, UserRole，继承 BaseEntity
• Configs/：EF Core 实体映射配置（Fluent API）
• AppDbContext.cs：EF Core 数据上下文
• Migrations/：EF Core 数据迁移记录（Code First）

---

4️⃣ Admin.NETCore.Common（通用功能层）

放置整个项目中通用的类和工具方法。

主要目录：

• Configs/：全局配置类，如 GlobalConfigs
• SqlHelper.cs：通用数据库操作帮助类（如直接操作 SQL）

---

项目文件结构图

依赖关系

完整层级

设计的用户表数据结构和返回结构

二、创建Web API项目

先创建一个带swagger的Web API项目然后再对其进行改造

打开 Visual Studio → 新建项目
选择 ASP.NET Core Web API
项目命名为：Admin.NETCore.API ，解决方案命名为：Admin.NETCore
勾选：
✔ 配置 HTTPS（可选）
✔ 勾选“使用控制器（取消选中以使用最小API)”（我们保留默认控制器）
✔ 启用 OpenAPI 支持（Swagger）

创建完成点击运行，可以看到浏览器的swagger页面

三、调整项目结构

右键解决方案，按下面步骤依次创建Admin.NETCore.Common，Admin.NETCore.Core，Admin.NETCore.Infrastructure，

右键解决方案 → 添加 → 新建项目
选择：类库 (.NET Class Library)
命名为：Admin.NETCore.Common，
选择NET 7.0 (或者创建完成后，右键项目 → 属性 → 将目标框架设置为 .NET 7.0)
创建

四、添加NuGet 包

官方文档：使用 NuGet 包管理器在 Visual Studio 中安装和管理包

使用 EFCore 和MySQL 需要添加以下NuGet包：

• Microsoft.EntityFrameworkCore.Tools
  EF Core 命令支持，用于数据库生成、迁移、生成表等操作，安装在Admin.NETCore.API内

• Pomelo.EntityFrameworkCore.MySql
  MySQL支持，安装在Admin.NETCore.Infrastructure内

如果是其他数据库参考下图 常见的数据库提供程序

五、通过CodeFirst建库建表

第一个EFCore应用

1)、先在Admin.NETCore.Infrastructure 下面创建文件夹和文件
2)、然后通过实体类定义用户表（User）的数据结构，使用 Fluent API 在独立的配置类中集中管理表名、主键、字段约束等数据库映射信息
3)、在数据库上下文(AppDbContext)中统一注册实体集合，并自动应用所有配置类
4)、最后使用 EF Core 提供的迁移与数据库更新命令（Add-Migration 和 Update-Database）即可在数据库中生成对应的 User 表结构，实现从代码到数据库的完整同步

BaseEntity代码

using System.ComponentModel.DataAnnotations.Schema;namespace Admin.NETCore.Infrastructure.DB.Entities
{public abstract class BaseEntity{//public Guid Id { get; set; }  // 使用 Guid 类型，表示 UUID// Guid.NewGuid().ToString().ToLower() 得到id//public string Id { get; set; } = null!;  // 存36位字符串 char    主键要定义基类中public DateTime CreateTime { get; set; }public DateTime UpdateDate { get; set; }public string? CreateBy { get; set; }public string? UpdateBy { get; set; }public bool IsDelete { get; set; } // 是否删除//[Column(TypeName = "DATETIME(6)")] // MySQL 支持高精度时间//public DateTime CreateTime { get; set; } = DateTime.UtcNow;//[Column(TypeName = "DATETIME(6)")]//public DateTime UpdateDate { get; set; } = DateTime.UtcNow;//[Column(TypeName = "VARCHAR(10)")] // 明确指定 VARCHAR 类型//public string CreateBy { get; set; } = "system";//[Column(TypeName = "VARCHAR(10)")]//public string UpdateBy { get; set; } = "system";//[Column(TypeName = "TINYINT(1)")] // MySQL 通常用 TINYINT 表示 bool//public bool IsDelete { get; set; }}
}

User代码

namespace Admin.NETCore.Infrastructure.DB.Entities
{public class User : BaseEntity{//public Guid Id { get; set; }  // 使用 Guid 类型，表示 UUID// Guid.NewGuid().ToString().ToLower() 得到idpublic string Id { get; set; } = null!;  // 存36位字符串 charpublic string Name { get; set; } = null!;  // 姓名public string LoginName { get; set; } = null!;  // 登录用户名public string Phone { get; set; } = null!;  // 手机号public int UserNumber { get; set; }  // 员工编号public string DeptId { get; set; } = null!;  // 部门IDpublic DateTime UserExpiryDate { get; set; }  // 用户有效期止public int Status { get; set; }  // 用户状态（1：启用，0：停用）public int Level { get; set; }  // 级别（1：一级，2：二级 。。。）public double? Money { get; set; }  // 补助，可为空public int? Age { get; set; }  // 年龄，可为空public string? Notes { get; set; }  // 备注，最多100个字符}
}

UserConfig代码

using Admin.NETCore.Infrastructure.DB.Entities;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;
using Microsoft.EntityFrameworkCore.Metadata.Builders;namespace Admin.NETCore.Infrastructure.DB.configs
{public class UserConfig : IEntityTypeConfiguration<User>{public void Configure(EntityTypeBuilder<User> builder){// 设置表名builder.ToTable("User");builder.HasKey(e => e.Id); // 设置主键// 属性配置builder.Property(e => e.Id).HasMaxLength(36);builder.Property(e => e.Name).HasMaxLength(10).IsRequired().HasComment("姓名");builder.Property(e => e.LoginName).HasMaxLength(10).HasColumnType("varchar(10)").IsRequired();builder.Property(e => e.Phone).HasMaxLength(11).IsRequired().IsFixedLength().HasAnnotation("PhoneNumber", "^[0-9]{11}$"); // 正则校验（可以自定义更复杂的格式）builder.Property(e => e.UserNumber).HasMaxLength(8).IsRequired();  // 数值类型（如 int）无法添加长度限制，此处HasMaxLength不生效builder.Property(e => e.DeptId).IsRequired(); // 不设置长度，类型为longtextbuilder.Property(e => e.UserExpiryDate).HasMaxLength(10).IsRequired(); // DateTime类型，无法添加长度限制，此处HasMaxLength不生效builder.Property(e => e.Status).IsRequired();builder.Property(e => e.Level).IsRequired();builder.Property(e => e.Money).IsRequired(false);builder.Property(e => e.Age).IsRequired(false).HasAnnotation("Age", "^[1-9][0-9]*$");builder.Property(e => e.Notes).HasMaxLength(100).IsRequired(false).HasComment("这是备注");// 公共属性配置builder.Property(e => e.CreateBy).IsRequired(false).HasMaxLength(10).HasColumnName("CreateBy");builder.Property(e => e.UpdateBy).IsRequired(false).HasMaxLength(10).HasColumnName("UpdateBy");// 创建时间（只设置一次）builder.Property(e => e.CreateTime).HasColumnName("CreateTime").HasColumnType("DATETIME(6)").ValueGeneratedOnAdd().HasDefaultValueSql("CURRENT_TIMESTAMP(6)") // GETDATE() SQL Server  / NOW() mysql  GETUTCDATE().Metadata.SetAfterSaveBehavior(PropertySaveBehavior.Ignore);// 更新时间（每次更新）builder.Property(e => e.UpdateDate).HasColumnName("UpdateDate").HasColumnType("DATETIME(6)").ValueGeneratedOnAddOrUpdate().HasDefaultValueSql("CURRENT_TIMESTAMP(6)") // .Metadata.SetAfterSaveBehavior(PropertySaveBehavior.Save);//builder.Ignore(e => e.CreateTime);// 设置某字段不映射到数据表//builder.Property(e => e.IsDelete).HasColumnName("delFlag"); // 某字段对应数据表的某字段}}
}/*EF默认规则是“主键属性不允许为空，引用类型允许为空，可空的值类型long?等允许为空，值类型不允许为空。”
基于“尽量少配置”的原则：如果属性是值类型并且允许为null，就声明成long?等，否则声明成long等；
如果属性属性值是引用类型，只有不允许为空的时候设置IsRequired()。其他一般不用设置的
主键：this.HasKey(p => p.pId);
某个字段不参与映射数据库：this.Ignore(p => p.Name1);
this.Property(p => p.Name).IsFixedLength(); 是否对应固定长度
this.Property(p => p.Name).IsUnicode(false) 对应的数据库类型是varchar类型，而不是nvarchar
this.Property(p => p.Id).HasColumnName(“Id”); Id列对应数据库中名字为Id的字段
this.Property(p=>p.Id).HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Identity) 指定字段是自动增长类型。*/

AppDbContext代码

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;
using System.Reflection;
using Admin.NETCore.Infrastructure.DB.Entities;namespace Admin.NETCore.Infrastructure.DB
{/// <summary>/// 应用数据库上下文，用于管理 EF Core 与数据库之间的交互/// </summary>public class AppDbContext : DbContext{public AppDbContext(DbContextOptions<AppDbContext> options) : base(options){}/*用户表（User 实体）对应的数据集合，AppDbContext 可以对 User 实体进行增删查改操作DbSet<T> 是 EF Core 中用于操作某个实体类型的集合放在 AppDbContext 中，EF Core 会自动识别这些属性，对应到数据库的表，进行 Code First 映射*/public DbSet<User> User { get; set; } //  DbSet<模型> 表名public DbSet<Role> Role { get; set; }public DbSet<UserRole> UserRole { get; set; }/** 数据库配置建议在 Program.cs 中完成（使用依赖注入方式）* 如果在这里同时使用 OnConfiguring，会导致配置冲突或冗余。* 所以此处注释掉 OnConfiguring 方法*///protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)//{//    // 数据库连接字符串//    var connectionString = "server=localhost;Database=TestDB;Uid=root;Pwd=root;";//    // 使用 MySQL 数据库，并指定服务器版本//    optionsBuilder.UseMySql(connectionString, ServerVersion.AutoDetect(connectionString));//     base.OnConfiguring(optionsBuilder);//}/// <summary>/// 模型构建方法，用于配置实体与数据库的映射关系/// </summary>protected override void OnModelCreating(ModelBuilder modelBuilder){// ❎ 下面是手动配置实体属性的示例，仅供参考，实际建议写在单独的配置类中//modelBuilder.Entity<User>().Property(e => e.Name)//    .IsRequired()//    .HasComment("备注");//modelBuilder.Entity<User>(entity =>//{//    entity.ToTable("User");//    // 属性配置//    entity.HasKey(e => e.Id); // 设置主键//    entity.Property(e => e.Id).HasMaxLength(36);//    entity.Property(e => e.Name).HasMaxLength(10).IsRequired().HasComment("姓名");//    entity.Property(e => e.LoginName).HasMaxLength(10).IsRequired();//    entity.Property(e => e.Phone).HasMaxLength(11).IsRequired().IsFixedLength().HasAnnotation("PhoneNumber", "^[0-9]{11}$"); // 正则校验（可以自定义更复杂的格式）//    entity.Property(e => e.UserNumber).HasMaxLength(8).IsRequired();//    entity.Property(e => e.DeptId).IsRequired();//    entity.Property(e => e.UserExpiryDate).HasMaxLength(10).IsRequired();//    entity.Property(e => e.Status).IsRequired();//    entity.Property(e => e.Level).IsRequired();//    entity.Property(e => e.Money).IsRequired(false);//    entity.Property(e => e.Age).IsRequired(false).HasAnnotation("Age", "^[1-9][0-9]*$");//    entity.Property(e => e.Notes).HasMaxLength(100).IsRequired(false).HasComment("这是备注");//});base.OnModelCreating(modelBuilder);//方式一. 分开注册, 逐个添加实体的配置类//modelBuilder.Configurations.Add(new UserConfig());//modelBuilder.Configurations.Add(new RoleConfig());//方式二. 一次性加载所有Fluent API的配置// ✅ 推荐方式：统一加载所有 IEntityTypeConfiguration 的配置类（如 UserConfig、RoleConfig 等）modelBuilder.ApplyConfigurationsFromAssembly(Assembly.GetExecutingAssembly());}}}/* Migration的一些命令(因为在Program中配置了 MigrationsAssembly对应的项目，这里放在配置的项目路径下) 工具>NuGet 包管理器 > 程序包管理器控制台Add-Migration Init update-database 指定 Migration 路径Add-Migration updateUserTable6 -OutputDir "DB/Migrations"*/

生成数据库和表

1）、在 Program.cs中注册 AppDbContext，并指定 EF Core 使用 MySQL 作为数据库

builder.Services.AddDbContext<AppDbContext>(options =>options.UseMySql(builder.Configuration.GetConnectionString("DefaultConnection"),ServerVersion.AutoDetect(builder.Configuration.GetConnectionString("DefaultConnection")),x => x.MigrationsAssembly("Admin.NETCore.Infrastructure") // 指定迁移程序集
));var app = builder.Build();

2）、在 appsettings中添加连接字符串

  "ConnectionStrings": {"DefaultConnection": "server=localhost;Database=TestDB;Uid=root;Pwd=root;"}

3）、生成Migration

// Install-Package Microsoft.EntityFrameworkCore.Tools
Add-Migration InitialCreate
Update-Database

通过Add-Migration xxx 命令生成Migration 迁移文件
作用：用于创建数据库迁移文件。根据当前的实体模型和配置类，生成一份数据库结构的变更快照（Migration 迁移文件）

4）、应用到数据库

通过Update-Database 命令将迁移应用到数据库中，创建相应的数据表结构

六、UserService 实现

1)、先在Admin.NETCore.Core 和Admin.NETCore.Common下面创建文件夹和文件
2)、在Service实现代码

Services主要代码

最新代码UserService.cs

UserDTO代码

using Admin.NETCore.Core.ViewModels.Base;namespace Admin.NETCore.Core.ViewModels
{public class UserDTO : BaseModel{public string Id { get; set; } = null!;public string Name { get; set; } = null!;public string LoginName { get; set; } = null!;public string Phone { get; set; } = null!;public int UserNumber { get; set; }public string DeptId { get; set; } = null!;public DateTime UserExpiryDate { get; set; }public int Status { get; set; }public int Level { get; set; }public double? Money { get; set; }public int? Age { get; set; }public string? Notes { get; set; }}
}

UserVModel代码

using Admin.NETCore.Core.ViewModels.Base;
using System.ComponentModel.DataAnnotations;namespace Admin.NETCore.Core.ViewModels
{public class UserVModel : BaseModel{public string? Id { get; set; }[Required(ErrorMessage = "Name不能为空")]public string Name { get; set; } = null!;[Required(ErrorMessage = "LoginName不能为空")]public string LoginName { get; set; } = null!;//[MaxLength(11, ErrorMessage = "Phone必须为11位")]//[MinLength(11, ErrorMessage = "Phone必须为11位")]//[StringLength(11, MinimumLength = 11, ErrorMessage = "Phone长度必须为11位[Required(ErrorMessage = "Phone不能为空")][RegularExpression(@"^1[3-9]\d{9}$", ErrorMessage = "手机号格式不正确")]public string Phone { get; set; } = null!;[Required(ErrorMessage = "UserNumber不能为空")][RegularExpression(@"^\d{8}$", ErrorMessage = "UserNumber必须为8位纯数字")]public int UserNumber { get; set; }[Required(ErrorMessage = "DeptId不能为空")]public string DeptId { get; set; } = null!;public DateTime UserExpiryDate { get; set; }public int Status { get; set; }[Range(1, 10, ErrorMessage = "Level需在0-10范围内")]public int Level { get; set; }public double? Money { get; set; }[Range(1, int.MaxValue, ErrorMessage = "Age必须是正整数")]public int? Age { get; set; }public string? Notes { get; set; }}public class UserFilterModel{public string? Name { get; set; }public string? UserNumber { get; set; }public string? DeptId { get; set; }public string? StartDate { get; set; }public string? EndDate { get; set; }public int Page { get; set; }public int Limit { get; set; }}public class AssignRoleVModel{[Required(ErrorMessage = "UserId不能为空")]public string Id { get; set; } = null!;public List<string> RoleIds { get; set; } = new();}
}

IUserService代码

using Admin.NETCore.Core.ViewModels;
using Admin.NETCore.Core.ViewModels.Base;namespace Admin.NETCore.Core.Interfaces
{public interface IUserService{Task<ApiResult<UserVModel>> CreateUserAsync(UserVModel user);Task<ApiResult<UserVModel>> UpdateUserAsync(UserVModel model);Task<ApiResult<UserVModel>> GetUserByIdAsync(string id);Task<ApiResult<string>> DeleteUserByIdAsync(string id);Task<PagedResult<UserDTO>> GetUserListAsync(UserFilterModel filter);}
}

UserService代码

using Microsoft.EntityFrameworkCore;
using Admin.NETCore.Common.Configs;
using Admin.NETCore.Core.Interfaces;
using Admin.NETCore.Core.ViewModels;
using Admin.NETCore.Core.ViewModels.Base;
using Admin.NETCore.Infrastructure.DB;
using Admin.NETCore.Infrastructure.DB.Entities;namespace Admin.NETCore.Core.Services
{public class UserService : IUserService{private readonly AppDbContext _context;public UserService(AppDbContext context){_context = context;}public async Task<ApiResult<UserVModel>> CreateUserAsync(UserVModel model){//var result = new ApiResult<UserVModel>();// 检查用户名是否已存在if (await _context.User.AnyAsync(m => m.LoginName == model.LoginName)){return ApiResult<UserVModel>.FailResult("登录名已存在");}var dbModel = new User{Id = Guid.NewGuid().ToString(),Name = model.Name,LoginName = model.LoginName,Phone = model.Phone,UserNumber = model.UserNumber,DeptId = model.DeptId,UserExpiryDate = model.UserExpiryDate,Status = model.Status,Level = model.Level,Money = model.Money,Age = model.Age,Notes = model.Notes,IsDelete = false};await _context.User.AddAsync(dbModel);await _context.SaveChangesAsync();var returnModel = model;returnModel.Id = dbModel.Id;return ApiResult<UserVModel>.SuccessResult(returnModel, "用户创建成功");}public async Task<ApiResult<UserVModel>> UpdateUserAsync(UserVModel model){var user = await _context.User.FindAsync(model.Id);if (user == null){return ApiResult<UserVModel>.FailResult("用户不存在");}//    检查用户名是否与其他用户重复if (await _context.User.AnyAsync(m => m.LoginName == model.LoginName && m.Id != model.Id)){return ApiResult<UserVModel>.FailResult("登录名已存在");}user.Name = model.Name;user.LoginName = model.LoginName;user.Phone = model.Phone;user.UserNumber = model.UserNumber;user.DeptId = model.DeptId;user.UserExpiryDate = model.UserExpiryDate;user.Status = model.Status;user.Level = model.Level;user.Money = model.Money;user.Age = model.Age;user.Notes = model.Notes;user.IsDelete = false;await _context.SaveChangesAsync();var returnModel = model;returnModel.Id = user.Id;return ApiResult<UserVModel>.SuccessResult(returnModel, "用户更新成功");}public async Task<ApiResult<string>> DeleteUserByIdAsync(string id){var user = await _context.User.FindAsync(id);if (user == null){return ApiResult<string>.FailResult("用户不存在");}_context.User.Remove(user); // 物理删除//user.IsDelete = true; // 逻辑删除await _context.SaveChangesAsync();return ApiResult<string>.SuccessResult("", "用户删除成功");}public async Task<ApiResult<UserVModel>> GetUserByIdAsync(string id){var user = await _context.User.FindAsync(id);if (user == null){return ApiResult<UserVModel>.FailResult("用户不存在");}var returnModel = new UserVModel{Id = user.Id,Name = user.Name,LoginName = user.LoginName,Phone = user.Phone,UserNumber = user.UserNumber,DeptId = user.DeptId,UserExpiryDate = user.UserExpiryDate,Status = user.Status,Level = user.Level,Money = user.Money,Age = user.Age,Notes = user.Notes,IsDelete = user.IsDelete};return ApiResult<UserVModel>.SuccessResult(returnModel);}public async Task<PagedResult<UserDTO>> GetUserListAsync(UserFilterModel filter){// 参数校验filter.Page = filter.Page > 0 ? filter.Page : 1;filter.Limit = filter.Limit > 0 ? filter.Limit : GlobalConfigs.DefaultPageSize;var query = _context.User.AsNoTracking().AsQueryable();/*EF Core 默认会追踪查询出来的实体（用于之后的更新或删除）如果只是读取数据，无需修改，可以用 .AsNoTracking() 提高性能它会 减少内存开销 和 避免不必要的跟踪逻辑*///var query = _context.User.Where(m => m.IsDelete == false).AsNoTracking().AsQueryable();//var query = _context.User.Where(m => !m.IsDelete).AsNoTracking();// 姓名模糊查询if (!string.IsNullOrEmpty(filter.Name))query = query.Where(m => EF.Functions.Like(m.Name, $"%{filter.Name}%"));// 员工编号模糊查询if (!string.IsNullOrEmpty(filter.UserNumber))query = query.Where(m => m.UserNumber.ToString().Contains(filter.UserNumber));// 部门ID模糊查询if (!string.IsNullOrEmpty(filter.DeptId))query = query.Where(m => m.DeptId == filter.DeptId);// 处理日期范围if (DateTime.TryParse(filter.StartDate, out DateTime startDate))query = query.Where(m => m.CreateTime >= startDate);if (DateTime.TryParse(filter.EndDate, out DateTime endDate))query = query.Where(m => m.CreateTime <= endDate);// 获取总数int total = await query.CountAsync();// 分页查询var users = await query.OrderByDescending(m => m.UpdateDate).Skip((filter.Page - 1) * filter.Limit).Take(filter.Limit).AsSplitQuery().Select(m => new UserDTO{Id = m.Id,Name = m.Name,LoginName = m.LoginName,Phone = m.Phone,UserNumber = m.UserNumber,DeptId = m.DeptId,UserExpiryDate = m.UserExpiryDate,Status = m.Status,Level = m.Level,Money = m.Money,Age = m.Age,Notes = m.Notes,IsDelete = m.IsDelete}).ToListAsync();return PagedResult<UserDTO>.SuccessResult(users, total);}}
}

七、UserController 实现

1)、先在Admin.NETCore.API 下面创建UserController文件
2)、在UserController实现代码
3)、在Program.cs 注册依赖注入

builder.Services.AddScoped<IUserService, UserService>();var app = builder.Build();

UserController代码

using Microsoft.AspNetCore.Mvc;
using Admin.NETCore.Core.Interfaces;
using Admin.NETCore.Core.ViewModels;
using Admin.NETCore.Core.ViewModels.Base;namespace Admin.NETCore.API.Controllers
{[ApiController][Route("api/[controller]/[action]")] // RPC风格, api/[控制器名称]/函数名称//[Route("api/[controller]")]  // RESTful 风格public class UserController : ControllerBase{private readonly IUserService _userService;public UserController(IUserService userService){_userService = userService;}[HttpPost]public async Task<ApiResult<UserVModel>> CreateUserAsync(UserVModel model){if (string.IsNullOrEmpty(model.LoginName)){return ApiResult<UserVModel>.FailResult("用户名不能为空");}return await _userService.CreateUserAsync(model);}[HttpPost]public async Task<ApiResult<UserVModel>> UpdateUserAsync(UserVModel model){if (string.IsNullOrEmpty(model.LoginName)){return ApiResult<UserVModel>.FailResult("用户名不能为空");}return await _userService.UpdateUserAsync(model);}//[HttpGet("{id}")] // 接口格式为 /api/user/GetUserById/123[HttpGet] // 接口格式为 /api/user/GetUserById?id=123public async Task<ApiResult<UserVModel>> GetUserByIdAsync(string id){if (string.IsNullOrEmpty(id)){return ApiResult<UserVModel>.FailResult("id不能为空");}return await _userService.GetUserByIdAsync(id);}[HttpPost]public async Task<ApiResult<string>> DeleteUserByIdAsync([FromBody] IDRequest request){if (string.IsNullOrEmpty(request.Id)){return ApiResult<string>.FailResult("id不能为空");}return await _userService.DeleteUserByIdAsync(request.Id);}[HttpGet]public async Task<PagedResult<UserDTO>> GetUserListAsync([FromQuery] UserFilterModel filter){return await _userService.GetUserListAsync(filter);}}
}

运行项目后，在swagger点创建用户接口 /api/User/CreateUser 和/api/User/GetUserList 如下

点创建用户接口 /api/User/CreateUser, 什么都不改，可以看到返回的数据并不是预期的结构，这是因为使用的是默认的校验，没有用自定义校验，在下一步优化

 {"code": 200,"msg": "success","data": {}}

八、优化Program.cs

现在Program.cs 完整代码如下，东西都写在一个文件了，以后如果加上像swagger配置、依赖注入、参数校验、中间件等，文件会越来越多，把代码都抽出来，保持主入口简洁

Program.cs原来的代码

using Admin.NETCore.Core.Interfaces;
using Admin.NETCore.Core.Services;
using Admin.NETCore.Infrastructure.DB;
using Microsoft.EntityFrameworkCore;var builder = WebApplication.CreateBuilder(args);// Add services to the container.builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();builder.Services.AddDbContext<AppDbContext>(options =>options.UseMySql(builder.Configuration.GetConnectionString("DefaultConnection"),ServerVersion.AutoDetect(builder.Configuration.GetConnectionString("DefaultConnection")),x => x.MigrationsAssembly("Admin.NETCore.Infrastructure") // 指定迁移程序集
));builder.Services.AddScoped<IUserService, UserService>();var app = builder.Build();// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{app.UseSwagger();app.UseSwaggerUI();
}app.UseHttpsRedirection();app.UseAuthorization();app.MapControllers();app.Run();

先把文件都创建好，然后在调整

ValidationFiter代码

// 自定义异常处理类
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Http;namespace Admin.NETCore.API.Identity.filters
{public class ValidationFilterAttribute : ActionFilterAttribute{public override void OnActionExecuting(ActionExecutingContext context){if (!context.ModelState.IsValid){// 提取所有错误信息var errorMessages = context.ModelState.Values.Where(x => x.Errors.Count > 0).SelectMany(x => x.Errors).Select(x => x.ErrorMessage).ToList();// 拼接错误信息为字符串var msgs = string.Join("; ", errorMessages);int statusCode = 201;// 构造自定义响应对象var response = new{code = statusCode,msg = msgs,success = false,data = ""};context.Result = new BadRequestObjectResult(response);// 自定义状态码//context.Result = new ObjectResult(response)//{//    StatusCode = statusCode //};}}}public class CustomValidationFilter : IAsyncActionFilter{public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next){if (!context.ModelState.IsValid){//var errorMessages = context.ModelState.Values//                    .Where(x => x.Errors.Count > 0)//                   .SelectMany(x => x.Errors)//                   .Select(x => x.ErrorMessage)//                   .ToList();//var msgs = string.Join("; ", errorMessages);//var response = new//{//    code = 201, // 可根据需求调整//    msg = msgs,//    success = false,//    data = ""//};//context.Result = new BadRequestObjectResult(response);context.Result = CreateValidationErrorResult(context.ModelState);return;}await next();}private static IActionResult CreateValidationErrorResult(ModelStateDictionary modelState){var errorMessages = modelState.Where(x => x.Value?.Errors.Count > 0).ToDictionary(x => x.Key,x => x.Value?.Errors.Select(error =>!string.IsNullOrEmpty(error.ErrorMessage)? error.ErrorMessage: error.Exception?.Message ?? "Unknown error").ToArray());var message = string.Join("; ", errorMessages.SelectMany(e => e.Value ?? Array.Empty<string>()));int statusCode = 201;var response = new{code = statusCode, // 可根据需求调整msg = message,errors = errorMessages,success = false,data = ""};return new BadRequestObjectResult(response); 自定义状态码//return new ObjectResult(response)//{//    StatusCode = statusCode//};}}
}

ApplicationBuilderExtensions代码

using Admin.NETCore.Infrastructure.DB;
using Microsoft.EntityFrameworkCore;namespace Admin.NETCore.API.ServiceExtensions
{public static class ApplicationBuilderExtensions{public static WebApplication ConfigureMiddlewarePipeline(this WebApplication app){// 异常处理应放在最前面app.UseExceptionHandler("/error");// Swaggerapp.UseCustomSwaggerUI();//app.UseCustomSwaggerUI22();if (app.Environment.IsDevelopment()){app.UseDeveloperExceptionPage();}else{app.UseHsts();app.UseHttpsRedirection();}app.UseRouting();// 健康检查端点app.MapHealthChecks("/health");// 全局日志中间件app.UseRequestLogging();app.UseCorsPolicy();app.UseAuthentication();app.UseAuthorization();app.MapControllers();// 可选：数据库自动迁移//app.ApplyMigrations<AppDbContext>();return app;}private static IApplicationBuilder UseRequestLogging(this IApplicationBuilder builder){return builder.Use(async (context, next) =>{var logger = context.RequestServices.GetRequiredService<ILogger<Program>>();logger.LogInformation("Request {Method} {Path}", context.Request.Method, context.Request.Path);await next();logger.LogInformation("Response {StatusCode}", context.Response.StatusCode);});}public static void ApplyMigrations<TContext>(this WebApplication app) where TContext : DbContext{using var scope = app.Services.CreateScope();var db = scope.ServiceProvider.GetRequiredService<TContext>();db.Database.Migrate();}}
}

CorsExtensions代码

namespace Admin.NETCore.API.ServiceExtensions
{public static class CorsExtensions{public static IServiceCollection AddCorsPolicy(this IServiceCollection services){// 配置跨域services.AddCors(c => c.AddPolicy("any", p => p.AllowAnyHeader().AllowAnyOrigin().AllowAnyMethod()));return services;}public static IApplicationBuilder UseCorsPolicy(this IApplicationBuilder app){app.UseCors("any");return app;}}
}

ServiceCollectionExtensions代码

using Admin.NETCore.API.Identity.filters;
using Admin.NETCore.Core.Interfaces;
using Admin.NETCore.Core.Services;
using Admin.NETCore.Infrastructure.DB;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;namespace Admin.NETCore.API.ServiceExtensions
{public static class ServiceCollectionExtensions{private const string MigrationAssembly = "Admin.NETCore.Infrastructure";public static IServiceCollection AddBasicServices(this IServiceCollection services, IConfiguration configuration){// Add services to the container.services.AddControllers();services.AddHealthChecks();// 日志配置services.AddLogging(logging =>{logging.AddConfiguration(configuration.GetSection("Logging"));logging.AddConsole();logging.AddDebug();});services.AddCorsPolicy();services.AddSwaggerConfig();// services.AddSwaggerConfig22();return services;}public static IServiceCollection AddDataBaseServices(this IServiceCollection services, IConfiguration configuration){var connectionString = configuration.GetConnectionString("DefaultConnection")?? throw new InvalidOperationException("缺少数据库连接字符串配置");// services.AddDbContext<AppDbContext>(options =>services.AddDbContextPool<AppDbContext>(options =>options.UseMySql(connectionString,ServerVersion.AutoDetect(connectionString),x => x.MigrationsAssembly(MigrationAssembly) // 指定迁移程序集));services.AddScoped<IUserService, UserService>();return services;}public static IServiceCollection AddControllerWithValidation(this IServiceCollection services){services.AddControllers(options =>{options.Filters.Add<ValidationFilterAttribute>();options.Filters.Add<CustomValidationFilter>();});// 禁用默认的模型验证响应services.Configure<ApiBehaviorOptions>(options =>{options.SuppressModelStateInvalidFilter = true;});return services;}}
}/* 数据库配置// 添加数据库上下文
//builder.Services.AddDbContext<AppDbContext>(options =>
//    options.UseMySql(
//        builder.Configuration.GetConnectionString("DefaultConnection"),
//        ServerVersion.AutoDetect(builder.Configuration.GetConnectionString("DefaultConnection"))
//    ));//builder.Services.AddDbContext<AppDbContext>(options =>
//    options.UseMySql(builder.Configuration.GetConnectionString("DefaultConnection"),
//        new MySqlServerVersion(new Version(8, 0, 21))));//builder.Services.AddDbContext<AppDbContext>(options =>
//    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));//  指定迁移程序集//builder.Services.AddDbContext<AppDbContext>(options =>
//    options.UseMySql(
//        builder.Configuration.GetConnectionString("DefaultConnection"),
//        ServerVersion.AutoDetect(builder.Configuration.GetConnectionString("DefaultConnection")),
//        x => x.MigrationsAssembly(Assembly.GetExecutingAssembly().GetName().Name)
//    ));*/

SwaggerExtensions代码

using Microsoft.AspNetCore.Mvc;
using Microsoft.OpenApi.Models;
using Swashbuckle.AspNetCore.SwaggerGen;// 通过[ApiExplorerSettings(GroupName = "v1")] 实现
namespace Admin.NETCore.API.ServiceExtensions
{public static class SwaggerExtensions{public static IServiceCollection AddSwaggerConfig(this IServiceCollection services){// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckleservices.AddEndpointsApiExplorer();//services.AddSwaggerGen();services.AddSwaggerGen(options =>{options.SwaggerDoc("v1", new OpenApiInfo{Title = "API (V1)",Version = "v1",//Description = "API 文档1",Description = "🚨 此版本已废弃，请使用 v2",});options.SwaggerDoc("v2", new OpenApiInfo{Title = "API (V2)",Version = "v2",Description = "API 文档2"});// 核心逻辑：根据 GroupName 过滤接口到对应文档options.DocInclusionPredicate((docName, apiDesc) =>{// 获取 Controller/Action 上的 GroupNamevar groupName = apiDesc.ActionDescriptor.EndpointMetadata.OfType<ApiExplorerSettingsAttribute>().FirstOrDefault()?.GroupName;// 未标记 GroupName 的接口默认显示在所有文档中if (string.IsNullOrEmpty(groupName)) return true;// 匹配当前 Swagger 文档名，只有标记了 GroupName 的接口才显示（如 v1/v2）return groupName == docName;});options.OperationFilter<InheritedObsoleteOperationFilter>(); // 注册自定义过滤器 解决 Schema ID 冲突问题//options.CustomSchemaIds(type => type.FullName); // 使用完整命名空间});return services;}public static WebApplication UseCustomSwaggerUI(this WebApplication app){// 获取 IConfigurationvar configuration = app.Services.GetRequiredService<IConfiguration>();// 获取配置EnableSwaggerbool enableSwagger = configuration.GetValue<bool>("EnableSwagger", false);if (app.Environment.IsDevelopment() && enableSwagger){app.UseSwagger();//app.UseSwaggerUI();app.UseSwaggerUI(c =>{c.SwaggerEndpoint("/swagger/v2/swagger.json", "versionV2"); // 这个顺序影响swagger select a definition 默认选中c.SwaggerEndpoint("/swagger/v1/swagger.json", "versionV1 (Deprecated)");// API 文档的默认展开方式c.DocExpansion(Swashbuckle.AspNetCore.SwaggerUI.DocExpansion.List); // 展开分组//c.DocExpansion(Swashbuckle.AspNetCore.SwaggerUI.DocExpansion.None); // 默认折叠//c.DocExpansion(Swashbuckle.AspNetCore.SwaggerUI.DocExpansion.Full); // 完全展开所有 API 的详细描述（包括请求参数、响应模型等）//c.DefaultModelsExpandDepth(-1); // -1：完全折叠，不显示任何模型详情。0：展开模型的顶层属性（单层展开）。1或更高：展开到指定层级。});}// 动态处理根路径重定向app.MapGet("/", context =>{if (enableSwagger){// 重定向到 Swagger 页面context.Response.Redirect("/swagger");return Task.CompletedTask;}else{// 返回其他信息（例如 API 状态）context.Response.ContentType = "text/plain; charset=utf-8";return context.Response.WriteAsync($"API 运行中（{(app.Environment.IsDevelopment() ? "Development" : "Production")}），Swagger 已禁用。");}});//app.Use(async (context, next) =>//{//    if (context.Request.Path == "/")//    {//        // 返回自定义响应//        context.Response.ContentType = "text/plain; charset=utf-8";//        await context.Response.WriteAsync("API 运行中，Swagger 已禁用");//        return;//    }//    await next();//});return app;}}// 若希望所有继承自 V1BaseController 的子类自动标记为废弃，可通过自定义过滤器实现。public class InheritedObsoleteOperationFilter : IOperationFilter{public void Apply(OpenApiOperation operation, OperationFilterContext context){// 检查控制器是否继承自带有 [Obsolete] 的基类var controllerType = context.MethodInfo.DeclaringType;var baseType = controllerType?.BaseType;if (baseType != null && baseType.GetCustomAttributes(typeof(ObsoleteAttribute), true).Any()){operation.Deprecated = true; // 标记操作已废弃operation.Description += " (已废弃：此接口所属控制器基类已废弃)";}}}
}

最后把Program.cs 调整一下，把Swagger配置项加到appsettings

  "EnableSwagger": true,

修改后的Program.cs代码

using Admin.NETCore.API.ServiceExtensions;var builder = WebApplication.CreateBuilder(args);// Services 配置
builder.Services.AddBasicServices(builder.Configuration);
builder.Services.AddDataBaseServices(builder.Configuration);
builder.Services.AddControllerWithValidation();//if (builder.Environment.IsDevelopment() && builder.Configuration.GetValue<bool>("EnableSwagger", false))
//{
//    builder.Services.AddSwaggerConfig();
//}var app = builder.Build();app.ConfigureMiddlewarePipeline();// Swagger
//if (builder.Environment.IsDevelopment() && builder.Configuration.GetValue<bool>("EnableSwagger", false))
//{
//    app.UseCustomSwaggerUI();
//}app.Run();

运行结果

运行后，页面如下

运行后，页面如下

至此结束