1、FluentValidation介绍
FluentValidation是与ASP.NET DataAnnotataion Attribute验证实体不同的数据验证组件，提供了将实体与验证分离开来的验证方式，同时FluentValidation还提供了表达式链式语法。
2、安装FluentValidation
FluentValidation地址：
使用Visual Studio的管理NuGet程序包安装FluentValidation及FluentValidation.Mvc
3、通过ModelState使用FluentValidation验证
项目解决方案结构图：
实体类Customer.cs:
using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace Libing.Portal.Web.Models.Entities{ public class Customer { public int CustomerID { get; set; } public string CustomerName { get; set; } public string Email { get; set; } public string Address { get; set; } public string Postcode { get; set; } public float? Discount { get; set; } public bool HasDiscount { get; set; } }} 数据验证类CustomerValidator.cs：
using System;using System.Collections.Generic;using System.Linq;using System.Web;using FluentValidation;using Libing.Portal.Web.Models.Entities;namespace Libing.Portal.Web.Models.Validators{ public class CustomerValidator : AbstractValidator { public CustomerValidator() { RuleFor(customer => customer.CustomerName).NotNull().WithMessage("客户名称不能为空"); RuleFor(customer => customer.Email) .NotEmpty().WithMessage("邮箱不能为空") .EmailAddress().WithMessage("邮箱格式不正确"); RuleFor(customer => customer.Discount) .NotEqual(0) .When(customer => customer.HasDiscount); RuleFor(customer => customer.Address) .NotEmpty() .WithMessage("地址不能为空") .Length(20, 50) .WithMessage("地址长度范围为20-50字节"); } }} 控制器类CustomerController.cs：
using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using FluentValidation.Results;using Libing.Portal.Web.Models.Entities;using Libing.Portal.Web.Models.Validators;namespace Libing.Portal.Web.Controllers{ public class CustomerController : Controller { public ActionResult Index() { return View(); } public ActionResult Create() { return View(); } [HttpPost] public ActionResult Create(Customer customer) { CustomerValidator validator = new CustomerValidator(); ValidationResult result = validator.Validate(customer); if (!result.IsValid) { result.Errors.ToList().ForEach(error => { ModelState.AddModelError(error.PropertyName, error.ErrorMessage); }); } if (ModelState.IsValid) { return RedirectToAction("Index"); } return View(customer); } }} View页面Create.cshtml，该页面为在添加View时选择Create模板自动生成：
@model Libing.Portal.Web.Models.Entities.Customer@{ Layout = null;} Create @using (Html.BeginForm()) { @Html.AntiForgeryToken() Customer
@Html.ValidationSummary(true) @Html.LabelFor(model => model.CustomerName, new { @class = "control-label col-md-2" }) @Html.EditorFor(model => model.CustomerName) @Html.ValidationMessageFor(model => model.CustomerName) @Html.LabelFor(model => model.Email, new { @class = "control-label col-md-2" }) @Html.EditorFor(model => model.Email) @Html.ValidationMessageFor(model => model.Email) @Html.LabelFor(model => model.Address, new { @class = "control-label col-md-2" }) @Html.EditorFor(model => model.Address) @Html.ValidationMessageFor(model => model.Address) @Html.LabelFor(model => model.Postcode, new { @class = "control-label col-md-2" }) @Html.EditorFor(model => model.Postcode) @Html.ValidationMessageFor(model => model.Postcode) @Html.LabelFor(model => model.Discount, new { @class = "control-label col-md-2" }) @Html.EditorFor(model => model.Discount) @Html.ValidationMessageFor(model => model.Discount) @Html.LabelFor(model => model.HasDiscount, new { @class = "control-label col-md-2" }) @Html.EditorFor(model => model.HasDiscount) @Html.ValidationMessageFor(model => model.HasDiscount) } 运行效果：
4、通过设置实体类Attribute与验证类进行验证
修改实体类Customer.cs：
using System;using System.Collections.Generic;using System.Linq;using System.Web;using FluentValidation.Attributes;using Libing.Portal.Web.Models.Validators;namespace Libing.Portal.Web.Models.Entities{ [Validator(typeof(CustomerValidator))] public class Customer { public int CustomerID { get; set; } public string CustomerName { get; set; } public string Email { get; set; } public string Address { get; set; } public string Postcode { get; set; } public float? Discount { get; set; } public bool HasDiscount { get; set; } }} 修改Global.asax.cs：
using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using System.Web.Routing;using FluentValidation.Attributes;using FluentValidation.Mvc;namespace Libing.Portal.Web{ public class MvcApplication : System.Web.HttpApplication { protected void Application_Start() { AreaRegistration.RegisterAllAreas(); RouteConfig.RegisterRoutes(RouteTable.Routes); // FluentValidation设置 DataAnnotationsModelValidatorProvider.AddImplicitRequiredAttributeForValueTypes = false; ModelValidatorProviders.Providers.Add(new FluentValidationModelValidatorProvider(new AttributedValidatorFactory())); } }}