枚举与功能的方法（组合类/枚举） [英] Enum with methods for functionality (Combine Class / Enum)

问题描述

我可能错过这里一些点，如果是这样的话 - 请包括讨论，因为我的问题的一部分。）

I may miss some sort of point here, if that's the case - please include that discussion as a part of my question :).

这是一个缩短下跌并更名的工作代码示例。所述GetTicks（..）是一个单一的样品，其可以是任何形式的功能性（的制造>值0 10 9 应返回一个特定的Enum a.so）。

This is a shortened down and renamed sample of a working code. The GetTicks(..) is a single sample, which could be any sort of functionality (value of > 0 < 9 should return a specific Enum a.so).

public static class Something
{
    public enum TypeOf : short
    {
        Minute = 2, Hour = 3, Day = 4, ........
    }

    public static long GetTicks(Something.TypeOf someEnum)
    {
        long ticks = 0;
        switch (someEnum)
        {
            case Something.TypeOf.Minute:
                ticks = TimeSpan.TicksPerMinute;
                break;
            case Something.TypeOf.Hour:
                ticks = TimeSpan.TicksPerHour;
                break;
         ....
        }
        return ticks;
    }
}


// This class is called from anywhere in the system.
public static void SomeMethod(string dodo, object o, Something.TypeOf period)
{
    // With the design above
    long ticks = Something.GetTicks(period);

    // Traditional, if there was a simple enum
    if (period == Something.Day)
        ticks = TimeSpan.FromDays(1).Ticks;
    else if (period == Something.Hour)
        ticks = TimeSpan.FromHours(1).Ticks;
}

我们的想法是收集涉及一个枚举，距离越近越好功能枚举本身。枚举的原因职能。此外，我发现很容易和自然来寻找附近的枚举这样的功能。也可以很容易地修改或扩展。

The idea is to collect functionality that concerns a enum, near as possible to the enum itself. The enum is the reason function. Also I find it easy and natural to look for such functionality near the enum. Also it's easy to modify or extend.

的缺点我都有，是我必须声明枚举更明确的 Something.TypeOf 。该设计可能看起来没有标准？如果枚举是在类内部使用也适用。

The drawback I have, is that I have to state the enum more explicit Something.TypeOf. The design may look no-standard? and would apply if the enum was for internal use in the class.

你会怎么做这个更漂亮？
我试图抽象，基地继承，局部的。他们似乎都不适用。

How would you do this more nice? I tried abstract, base inheritance, partial. None of them seem to apply.

推荐答案

C＃枚举不喜欢这个工作。然而，你可以很轻松地实现自己的固定的值：

C# enums don't work well like this. However, you can implement your own "fixed set of values" fairly easily:

public sealed class Foo
{
    public static readonly Foo FirstValue = new Foo(...);
    public static readonly Foo SecondValue = new Foo(...);

    private Foo(...)
    {
    }

    // Add methods here
}

碰巧的是，其中一个例子，我得到了，这是非常相似你的 - 的 DateTimeFieldType 在<一个HREF =https://github.com/nodatime/nodatime相对=nofollow>野田佳彦时间。有时你甚至可能要进行启封类，但保留私有构造 - 它允许你创建子类的只为嵌套类的。 。非常方便的限制继承

As it happens, one example I've got of this is remarkably similar to yours - DateTimeFieldType in Noda Time. Sometimes you might even want to make the class unsealed, but keep the private constructor - which allows you to create subclasses only as nested classes. Very handy for restricting inheritance.

缺点是，你不能使用开关：（

The downside is that you can't use switch :(

这篇关于枚举与功能的方法（组合类/枚举）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！