Asp .Net Core 集成 FluentValidation 强类型验证规则库

入门程序
- 安装
- 案例：登录
验证器
- 内置验证器
- 自定义验证器
  - 编写自定义验证器
  - 可重复使用的属性验证器
本地化
DI
自动验证

官网：https://docs.fluentvalidation.net/en/latest/index.html

入门程序

安装

使用 Visual Studio 中的 NuGet 包管理器控制台运行以下命令：

shell 复制代码

Install-Package FluentValidation

或者从终端窗口使用 .net core CLI：

shell 复制代码

dotnet add package FluentValidation

案例：登录

编写通用返回类

c# 复制代码

namespace FluentValidationTest
{
    public class Result
    {
        public string Message { get; set; }

        public int Code { get; set; }

        public dynamic Data { get; set; }

        public static Result Success(dynamic data = null)
        {
            Result result = new Result();
            result.Data = data;
            result.Code = 1;
            result.Message = "success.";
            return result;
        }

        public static Result Fail(string message)
        {
            Result result = new Result();
            result.Code = 0;
            result.Message = message;
            return result;
        }
    }
}

编写登录请求类

c# 复制代码

using System.ComponentModel;

namespace FluentValidationTest
{
    public class LoginRequest
    {
        [Description("用户名")]
        public string UserName { get; set; }

        [Description("密码")]
        public string Password { get; set; }
    }
}

编写登录请求验证类

c# 复制代码

using FluentValidation;

namespace FluentValidationTest
{
    public class LoginRequestValidator : AbstractValidator<LoginRequest>
    {
        public LoginRequestValidator()
        {
            RuleFor(x => x.UserName).NotEmpty().WithMessage("用户名不能为空");
            RuleFor(x => x.Password).NotEmpty().WithMessage("密码不能为空");
            RuleFor(x => x.Password).MinimumLength(6).MaximumLength(20).WithErrorCode("-200").WithMessage("密码长度在6-20");
        }
    }
}

编写用户控制器

c# 复制代码

using FluentValidation.Results;
using Microsoft.AspNetCore.Mvc;

namespace FluentValidationTest.Controllers
{
    [ApiController]
    [Route("[controller]/[action]")]
    public class UserController : ControllerBase
    {
        [HttpPost]
        public async Task<Result> Login(LoginRequest request)
        {
            LoginRequestValidator validations = new LoginRequestValidator();
            //验证
            ValidationResult validationResult = validations.Validate(request);
            if (!validationResult.IsValid)
            {
                return Result.Fail(validationResult.Errors[0].ErrorMessage);
            }
            return Result.Success();
        }
    }
}

测试

验证器

内置验证器

网站：https://docs.fluentvalidation.net/en/latest/built-in-validators.html

NotNull Validator
NotEmpty Validator
NotEqual Validator
Equal Validator
Length Validator
MaxLength Validator
MinLength Validator
Less Than Validator
Less Than Or Equal Validator
Greater Than Validator
Greater Than Or Equal Validator
Predicate Validator
Regular Expression Validator
Email Validator
Credit Card Validator
Enum Validator
Enum Name Validator
Empty Validator
Null Validator
ExclusiveBetween Validator
InclusiveBetween Validator
PrecisionScale Validator

自定义验证器

编写自定义验证器

c# 复制代码

            RuleFor(x => x.UserName).Custom((userName, context) =>
            {
                if (!userName.Contains("admin"))
                {
                    context.AddFailure("not amdin.");
                }
            });

可重复使用的属性验证器

在某些情况下，您的自定义逻辑非常复杂，您可能希望将自定义逻辑移至单独的类中。这可以通过编写一个继承抽象类的类来完成 PropertyValidator<T,TProperty>（这是 FluentValidation 的所有内置规则的定义方式）。

c# 复制代码

using FluentValidation.Validators;
using FluentValidation;

namespace FluentValidationTest
{
    /// <summary>
    /// 条件验证器
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <typeparam name="TProperty"></typeparam>
    public class ConditionValidator<T, TProperty> : PropertyValidator<T, TProperty>
    {
        Func<T, TProperty, bool> _func;

        string _message;

        /// <summary>
        ///
        /// </summary>
        /// <param name="func">委托</param>
        /// <param name="message">提示消息</param>
        public ConditionValidator(Func<T, TProperty, bool> func, string message)
        {
            _func = func;
            _message = message;
        }

        public override string Name => "ConditionValidator";

        public override bool IsValid(ValidationContext<T> context, TProperty value)
        {
            return _func.Invoke(context.InstanceToValidate, value);
        }

        protected override string GetDefaultMessageTemplate(string errorCode)
          => _message;
    }

    /// <summary>
    /// 扩展类
    /// </summary>
    public static class ValidatorExtensions
    {
        public static IRuleBuilderOptions<T, TElement> Condition<T, TElement>(this IRuleBuilder<T, TElement> ruleBuilder, Func<T, TElement, bool> func, string message)
        {
            return ruleBuilder.SetValidator(new ConditionValidator<T, TElement>(func, message));
        }
    }
}

使用

c# 复制代码

 RuleFor(x => x.UserName).Condition((a, b) => a.UserName.Contains("admin"),"不符合条件");

本地化

如果您想替换 FluentValidation 的全部（或部分）默认消息，则可以通过实现接口的自定义版本来实现 ILanguageManager。

例如，NotNull 验证器的默认消息是。如果您想为应用程序中验证器的所有使用替换此消息，您可以编写一个自定义语言管理器：'{PropertyName}' must not be empty.

c# 复制代码

using FluentValidation.Resources;
using FluentValidation.Validators;

namespace FluentValidationTest
{
    public class CustomLanguageManager : LanguageManager
    {
        public CustomLanguageManager()
        {
            AddTranslation("en", "NotEmptyValidator", "{PropertyName} 值为空");
            AddTranslation("en", "MinimumLengthValidator", "{PropertyName} {PropertyValue} 小于 {MinLength}");
        }

    }
}

Program 类

c# 复制代码

ValidatorOptions.Global.LanguageManager = new CustomLanguageManager();

DI

https://docs.fluentvalidation.net/en/latest/di.html

shell 复制代码

Install-Package FluentValidation.DependencyInjectionExtensions

Program.cs添加

c# 复制代码

            builder.Services.AddValidatorsFromAssemblyContaining<LoginRequestValidator>();
            //builder.Services.AddValidatorsFromAssembly(Assembly.Load("FluentValidationTest"));

控制器实现

c# 复制代码

    public class UserController : ControllerBase
    {
        private LoginRequestValidator _loginRequestValidator;
        public UserController(LoginRequestValidator loginRequestValidator)
        {
            _loginRequestValidator = loginRequestValidator;
        }
    }

自动验证

https://github.com/SharpGrip/FluentValidation.AutoValidation

安装 nuget 包

shell 复制代码

Install-Package SharpGrip.FluentValidation.AutoValidation.Mvc

配置

c# 复制代码

using SharpGrip.FluentValidation.AutoValidation.Mvc.Extensions;

builder.Services.AddFluentValidationAutoValidation(configuration =>
{
    // Disable the built-in .NET model (data annotations) validation.
    configuration.DisableBuiltInModelValidation = true;

    // Only validate controllers decorated with the `FluentValidationAutoValidation` attribute.
    configuration.ValidationStrategy = ValidationStrategy.Annotation;

    // Enable validation for parameters bound from `BindingSource.Body` binding sources.
    configuration.EnableBodyBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from `BindingSource.Form` binding sources.
    configuration.EnableFormBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from `BindingSource.Query` binding sources.
    configuration.EnableQueryBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from `BindingSource.Path` binding sources.
    configuration.EnablePathBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from 'BindingSource.Custom' binding sources.
    configuration.EnableCustomBindingSourceAutomaticValidation = true;

    // Replace the default result factory with a custom implementation.
    configuration.OverrideDefaultResultFactoryWith<CustomResultFactory>();
});

自定义返回结果

c# 复制代码

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using SharpGrip.FluentValidation.AutoValidation.Mvc.Results;

namespace FluentValidationTest
{
    public class CustomResultFactory : IFluentValidationAutoValidationResultFactory
    {
        public IActionResult CreateActionResult(ActionExecutingContext context, ValidationProblemDetails? validationProblemDetails)
        {
            return new JsonResult(Result.Fail(validationProblemDetails.Errors.Values.FirstOrDefault()[0]));
        }
    }
}