使用 Fluent Validation 如何检查对象中的两个属性都不能有值？

Question

I want to validate two properties ( MyProperty1 , MyProperty2 ) in a class. These properties can both be null. They both have separate validation rules but they cannot both have a value set.

public MyObject 
{
    public string MyProperty1 { get; set; }
    public string MyProperty2 { get; set; }
}

I am trying to avoid writing something like this

            When(
            c => c.MyProperty1 != null && c.MyProperty2 != null,
            () =>
                this.RuleFor(r => r.MyProperty1 )
                    .Null()
                    .WithMessage("MyProperty1 must be null when MyProperty2 has value"));

Answer 1

The following will achieve that and keeps the fluent readability.

RuleFor(o => o.MyProperty1)
    .Null()
    .When(o => o.MyProperty2 != null)
    .WithMessage("MyProperty1 must be null when MyProperty2 has value");

RuleFor(o => o.MyProperty2)
    .Null()
    .When(o => o.MyProperty1 != null)
    .WithMessage("MyProperty2 must be null when MyProperty1 has value");