c# - Fluentvalidation 仅在填充字段时验证

Question

我有一个小数字段，例如:

public decimal Limit {get; set;}

现在，我正在尝试对以下规则使用流畅的验证:

This field is not mandatory but if it IS populated, then validate its greater than 0. If it isn't populated, then ignore it

我该怎么做？我的问题是小数点默认为 0，那么如何确定它是否填充了 0？

我一直在尝试类似的东西:

When(x => x.Limit== 0, () =>
{
  RuleFor(x => x.Limit)
    .Empty()
    .GreaterThan(0)
    .WithMessage("{PropertyName} sflenlfnsle Required");
})

Answer 1

如评论中所述，区分未设置(因此具有默认值)和已设置为默认值的值类型的唯一方法是将类型更改为可为空类型。

void Main()
{

    var example1 = new SomeType();                  // Limit not set, should pass validation
    var example2 = new SomeType(){Limit = 0};       // Limit set, but illegal value, should fail validation
    var example3 = new SomeType(){Limit = 10.9m};   // Limit set to legal value, should pass validation

    var validator = new SomeTypeValidator();

    Console.WriteLine(validator.Validate(example1).IsValid);    // desired is 'true'
    Console.WriteLine(validator.Validate(example2).IsValid);    // desired is 'false'
    Console.WriteLine(validator.Validate(example3).IsValid);    // desired is 'true'
}


public class SomeType
{
    public Decimal? Limit { get; set; }
}

public class SomeTypeValidator : AbstractValidator<SomeType>
{
    public SomeTypeValidator()
    {
        RuleFor(r=>r.Limit.Value)
            .NotEmpty()
            .When(x=> x.Limit.HasValue);
    }
}