闲话 Asp.Net Core 数据校验（三）EF Core 集成 FluentValidation 校验数据例子

前言

一个在实际应用中 EF Core 集成 FluentValidation 进行数据校验的例子。

Step By Step 步骤

创建一个 Asp.Net Core WebApi 项目
引用以下 Nuget 包

FluentValidation.AspNetCore

Microsoft.AspNetCore.Identity.EntityFrameworkCore

Microsoft.EntityFrameworkCore.Relational

Microsoft.EntityFrameworkCore.SqlServer

Microsoft.EntityFrameworkCore.Tools

创建 Login 操作方法的请求参数模型类 LoginRequest

c# 复制代码

// LoginRequest 类只是一个普通的C#类，
// 没有标注任何的Attribute或者实现任何的接口，
// 它的唯一责任就是传递数据
public record LoginRequest(string Email, string Password, string PasswordConfirm);

修改 appsettings.json，添加数据库连接字符串

复制代码

{
  "Logging": {
	"LogLevel": {
	  "Default": "Information",
	  "Microsoft.AspNetCore": "Warning"
	}
  },
  "AllowedHosts": "*",
  "ConnectionStrings": {
	"Default": "Server=(localdb)\\mssqllocaldb;Database=IdentityTestDB;Trusted_Connection=True;MultipleActiveResultSets=true"
  }
}

创建用户实体类User和Role

c# 复制代码

using Microsoft.AspNetCore.Identity;

public class User : IdentityUser<long>
{
	public DateTime CreationTime { get; set; }
	public string? NickName { get; set; }
}

public class Role : IdentityRole<long>
{

}

创建继承自IdentityDbContext的上下文类

c# 复制代码

using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;

public class TestDbContext : IdentityDbContext<User, Role, long>
{
	public TestDbContext(DbContextOptions<TestDbContext> options)
		: base(options)
	{

	}
	protected override void OnModelCreating(ModelBuilder modelBuilder)
	{
		base.OnModelCreating(modelBuilder);
		modelBuilder.ApplyConfigurationsFromAssembly(this.GetType().Assembly);
	}
}

打开 Program.cs，注册 Identity 和 FluentValidation

c# 复制代码

using FluentValidation;
using FluentValidation.AspNetCore;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using System.Reflection;

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();

// 注册标识框架相关的服务，并配置相关选项
IServiceCollection services = builder.Services;
services.AddDbContext<TestDbContext>(opt =>
{
	string connStr = builder.Configuration.GetConnectionString("Default")!;
	opt.UseSqlServer(connStr);
});
services.AddDataProtection();
services.AddIdentityCore<User>(options =>
{
	options.Password.RequireDigit = false;
	options.Password.RequireLowercase = false;
	options.Password.RequireNonAlphanumeric = false;
	options.Password.RequireUppercase = false;
	options.Password.RequiredLength = 6;
	options.Tokens.PasswordResetTokenProvider = TokenOptions.DefaultEmailProvider;
	options.Tokens.EmailConfirmationTokenProvider = TokenOptions.DefaultEmailProvider;
});
var idBuilder = new IdentityBuilder(typeof(User), typeof(Role), services);
idBuilder.AddEntityFrameworkStores<TestDbContext>()
	.AddDefaultTokenProviders()
	.AddRoleManager<RoleManager<Role>>()
	.AddUserManager<UserManager<User>>();

// 注册 FluentValidation 服务
Assembly assembly = Assembly.GetExecutingAssembly();
builder.Services.AddFluentValidationAutoValidation()
	.AddFluentValidationClientsideAdapters()
	.AddValidatorsFromAssembly(assembly);

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();

编写请求参数模型类 LoginRequest

c# 复制代码

public record LoginRequest(string UserName, string Password);

编写继承自AbstractValidator的数据校验类，留意注释

c# 复制代码

using FluentValidation;
using Microsoft.EntityFrameworkCore;

public class LoginRequestValidator : AbstractValidator<LoginRequest>
{
	// 通过构造方法注入了TestDbContext
	public LoginRequestValidator(TestDbContext dbCtx)
	{
		RuleFor(x => x.UserName)
			.NotNull()
			// 使用TestDbContext服务检查用户名是否存在
			// 同步方式
			.Must(name => dbCtx.Users.Any(u => u.UserName == name))
			// 异步方式，但使用异步后出错，暂时未能找到解决方案
			//.MustAsync((name,_) => dbCtx.Users.AnyAsync(u => u.UserName == name))
			// 用Lambda表达式的形式使用模型类中的属性对报错信息进行格式化
			.WithMessage(c => $"用户名{c.UserName}不存在");
	}
}

打开登录请求控制器，编写 Login API

c# 复制代码

using Microsoft.AspNetCore.Mvc;

namespace FluentValidationSample2.Controllers
{
	[ApiController]
	[Route("[controller]/[action]")]
	public class TestController : ControllerBase
	{
		[HttpPost]
		public ActionResult Login(LoginRequest req)
		{
			return Ok();
		}
	}
}

在 Postman 或 Swagger 测试 Login API，如果请求的用户名不存在，即会返回代码中定义的错误信息