FluentValidation.AspNetCore 在.NET Core 6.0上使用的技巧和问题

FluentValidation.AspNetCore11.0.0.0

.NET Core 6.0

1.为什么使用FluentValidation?

一个原因是自定义属性验证代码要写很多，模型中的每个需要验证的字段，都需要独立的编写相应的自定义属性。FluentValidation对字段的验证代码需要的相对来说少了点。添加字段校验更简单。

另一个原因：对参数校验进行了解耦，使用AOP分离了验证功能。

2.验证顺序FluentValidation与Attribute

模型绑定-模型验证（Attribute）-FluentValidation

3.可空字段验证，可空字段如果有二阶段验证。例如可空的邮箱格式验证

public class EmailReqValidator : AbstractValidator<EmailReq>
{
    public PlatformUserUpdateReqValidator()
    {
        RuleFor(_ => _.Email).EmailAddress().WithMessage("邮箱格式输入有误");
    }
}
 
public class EmailReq
{
    /// <summary>
    /// 邮箱
    /// </summary>
    [DisplayName("邮箱")]
    public string? Email { get; set; }
}

(1)null能通过验证

{
  "email":null
}

(2)""不能通过验证，提示：邮箱输入有误

{
  "email":"",
}

（3）不传递参数，不能通过验证，提示：邮箱输入有误

{
}

如果想要""和不传递参数时，通过校验，建议调整验证规则

public class EmailReqValidator : AbstractValidator<EmailReq>
{
    public PlatformUserUpdateReqValidator()
    {
        RuleFor(_ => _.Email).When(x=>!string.IsNullOrEmpty(x.Email)).EmailAddress().WithMessage("邮箱格式输入有误");
    }
}

4.FluentValidation CascadeMode全局设置

CascadeMode可以设置如果验证失败单个字段仅验证一次，单个类仅验证一次。

（1）设置模型类的CascadeMode，当模型的第一个验证失败，后续验证不执行。

ValidatorOptions.Global.DefaultClassLevelCascadeMode = CascadeMode.Stop;

（1）设置模型字段的CascadeMode，当字段的第一个验证失败，后续验证不执行。

ValidatorOptions.Global.DefaultRuleLevelCascadeMode = CascadeMode.Stop;

这两个设置放到启动文件里面就可以，比如Program.cs文件，跟着FluentValidation注入代码即可。

services.AddFluentValidationAutoValidation();//Fluent参数验证
ValidatorOptions.Global.DefaultClassLevelCascadeMode = CascadeMode.Stop;
ValidatorOptions.Global.DefaultRuleLevelCascadeMode = CascadeMode.Stop;

5.IsEnum 枚举验证，默认值也校验失败（待优化）

public class BannerUpdateReqValidator : AbstractValidator<BannerUpdateReq>
{
    public BannerUpdateReqValidator()
    { 
    RuleFor(_ => _.Type).IsInEnum()
     .WithMessage("枚举输入有误")
     .Must((x, y) => { return x.Type != BannerEnum.DEFAULT; })
     .WithMessage("枚举输入有误");
     }
 }
 
public enum BannerEnum
{
    /// <summary>
    /// 默认
    /// </summary>
    [Description("默认")]
    DEFAULT = -1,
    /// <summary>
    /// 后台Banner
    /// </summary>
    [Description("后台Banner")]
    BANNER = 0,
}
 
public class BannerUpdateReq
{
    public BannerEnum Type { get; set; }
}

6.Fluenvalidation复杂模型校验，如：List集合

list集合借助foreach处理，本质上还是对list对象实体创建独立的校验规则。

/// <summary>
/// 商户入驻入参
/// </summary>
public class MerchantAddReq : BaseAddReq
{
 
    /// <summary>
    /// 入驻信息
    /// </summary>
    public OrganizationAddReq? OrganizationModel { get; set; }
 
    /// <summary>
    /// 入驻资料映射实体
    /// </summary>
    public List<AttachmentAddReq>? AttachmentList { get; set; }
}

/// <summary>
/// 查询分页数据（含条件）
/// </summary>
public class MerchantAddReqValidator : AbstractValidator<MerchantAddReq>
{
    public MerchantAddReqValidator()
    {
        RuleFor(_ => _.OrganizationModel).NotNull().WithMessage(StatusCodeEunm.CODE_MERCHANT_MODEL_EMPTY.GetDescription());
        RuleFor(_ => _.OrganizationModel.OrganizationName).NotEmpty()
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ORGANIZATION_NAME_EMPTY.GetDescription());
        RuleFor(_ => _.OrganizationModel.Logo).NotEmpty()
           .WithMessage(StatusCodeEunm.CODE_NEWS_PIC_EMPTY.GetDescription())
           .Must(BaseValidator.UrlValidate).WithMessage(StatusCodeEunm.CODE_NEWS_PIC_INPUT.GetDescription());
        RuleFor(_ => _.OrganizationModel.RegistrationType).IsInEnum()
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_REGISTRATION_TYPE_INPUT.GetDescription())
           .Must(e => e == RegisterEnum.PERSERON || e == RegisterEnum.INSTITUTION)
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_REGISTRATION_TYPE_INPUT.GetDescription());
        RuleFor(_ => _.OrganizationModel.Email).EmailAddress().
            When(e => e.OrganizationModel != null && !string.IsNullOrEmpty(e.OrganizationModel.Email))
            .WithMessage(StatusCodeEunm.CODE_EMAIL_INPUT.GetDescription());
        RuleFor(_ => _.OrganizationModel.Name).NotEmpty()
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_NAME_EMPTY.GetDescription());
        RuleFor(_ => _.OrganizationModel.Mobile).Must(BaseValidator.MobileValidate)
           .WithMessage(StatusCodeEunm.CODE_MOBILE_INPUT.GetDescription());
        RuleFor(_ => _.AttachmentList).NotEmpty()
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_EMPTY.GetDescription())
           .ForEach(e => e.SetValidator(new AttachmentAddReqValidator()));
    }
}
 
/// <summary>
/// 证书校验
/// </summary>
public class AttachmentAddReqValidator : AbstractValidator<AttachmentAddReq>
{
    public AttachmentAddReqValidator()
    {
        RuleFor(_ => _.Type).IsInEnum().WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_TYPE_INPUT.GetDescription())
            .Must((x, y) => x.Type != AttachmentTypeEnum.DEFAULT)
            .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_TYPE_INPUT.GetDescription());
        RuleFor(_ => _.Code).NotEmpty()
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_CODE_EMPTY.GetDescription());
        RuleFor(_ => _.ImagePath).NotEmpty()
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_PIC_EMPTY.GetDescription())
           .Must(BaseValidator.UrlValidate)
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_PIC_INPUT.GetDescription());
        RuleFor(_ => _.IsLongEffect)
           .Must(e => e == 0 || e == 1)
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_LIMIT_INPUT.GetDescription());
        RuleFor(_ => _.Limit).NotEmpty().When(e => e.IsLongEffect == 0)
           .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_LIMIT_INPUT.GetDescription());
        RuleFor(_ => _.TeachingField).Must(BaseValidator.IDValidate)
            .WithMessage(StatusCodeEunm.CODE_MERCHANT_ATTACHMENT_FIELD_INPUT.GetDescription());
    }
}