如何在對象中引用屬性以每次重新評估它們

Question

我嘗試使用字典將一些enum映射到許多bool屬性：

private Dictionary<FooEnum, bool> isBarByFoo;

private Dictionary<FooEnum, bool> IsBarByFoo
{
    get
    {
        return isBarByFoo ?? (isBarByFoo = new Dictionary<FooEnum, bool>
        {
            { FooEnum.Foo1, IsBar1 },
            { FooEnum.Foo2, IsBar2 },
            { FooEnum.Foo3, IsBar3 }
        });
    }
}

private bool IsBar1 => SomeConditionsThatChangeOverRuntime1();
private bool IsBar2 => SomeConditionsThatChangeOverRuntime2();
private bool IsBar3 => SomeConditionsThatChangeOverRuntime3();

但是，這種方法行不通，因為創建字典並將其保存為值類型時僅對屬性進行一次評估，結果我誤解了屬性的工作方式。

是否可以將屬性存儲在字典中，從而在每次查找屬性時對其進行評估，或者您可以針對這種問題提出不同的解決方案嗎？

Answer 1

關於什么：

    private Dictionary<FooEnum, Func<bool>> isBarByFoo;

    private Dictionary<FooEnum, Func<bool>> IsBarByFoo
    {
        get
        {
            return isBarByFoo ?? (isBarByFoo = new Dictionary<FooEnum, Func<bool>>
            {
                { FooEnum.Foo1, SomeConditionsThatChangeOverRuntime1},
                { FooEnum.Foo2, SomeConditionsThatChangeOverRuntime2},
                { FooEnum.Foo3, SomeConditionsThatChangeOverRuntime3}
            });
        }
    }

    private bool SomeConditionsThatChangeOverRuntime1() => true;
    private bool SomeConditionsThatChangeOverRuntime2() => false;
    private bool SomeConditionsThatChangeOverRuntime3() => true;

當您通過IsBarByFoo[FooEnum.Foo1]()獲得字典的值時，您將獲得所需的值

Answer 2

另一個解決方案可能是忘記字典，而只是使用一種方法來獲取值：

private bool GetIsBarByFoo(FooEnum foo)
{
    switch (foo)
    {
        case FooEnum.Foo1:
           return SomeConditionsThatChangeOverRuntime1();
        case FooEnum.Foo2:
           return SomeConditionsThatChangeOverRuntime2();
        case FooEnum.Foo3:
           return SomeConditionsThatChangeOverRuntime3();
        default:
           return false;
    }
}