是否有可能保存类型（使用" typeof运算（）"）在一个枚举？ [英] Is it possible to save a Type (using "typeof()") in an enum?
问题描述
所以，我创造了XNA游戏，C＃4.0中，我需要管理大量的通电（这在代码都是从班的上电继承），并处理通电的后台管理我目前有一个枚举，PowerupEffectType，对每个子类的上电的价值。最后，在我需要从PowerupEffectType做转换到通电的类型（类的代码键入与通常实现的typeof（[类别名称]））
So I'm creating a game in XNA, C# 4.0, and I need to manage a lot of PowerUps (which in code are all inherited from class "PowerUp"), and to handle back-end management of the PowerUps I currently have an enum, PowerupEffectType, with a value for each child class of PowerUp. Eventually in the code I need to do conversions from PowerupEffectType to the Powerup type (of class Type, achieved usually with typeof([class name])).
由于这是一个团体项目，我想PowerupEffectType的每个值嫁给其对应的类类型以及可能的，即：不只是希望我的其他程序员使用switch语句做手工转换，并确保添加/扩展以后包括在尽可能少的地方尽可能少的变化。我有这几个选项，到目前为止，我发现最好的是创建枚举伪的方法都浓缩到一个switch语句（我想要的99％），这得益于一些小技巧，我发现在这里：< A HREF =http://msdn.microsoft.com/en-us/library/bb383974.aspx> http://msdn.microsoft.com/en-us/library/bb383974.aspx
Since this is a group project, I want to marry each value of PowerupEffectType to its corresponding class Type as well as possible, i.e.: Not just expect my other programmers to use switch statements to do the conversion manually, and making sure additions/expansions later involve as few changes in as few places as possible. I have a few options for this, and the best I've discovered so far is creating enum pseudo-methods that condense everything down to a single switch statement (99% of what I want), thanks to some tips I found here: http://msdn.microsoft.com/en-us/library/bb383974.aspx
不过，我试图把它一步 - 我节省键入在枚举 我知道你可以保存为枚举特定类型（链接：http://msdn.microsoft.com/en-us/library/cc138362.aspx ），但键入不是一他们的。目前的选择是的字节，为sbyte，短，USHORT，INT，UINT，long和ulong 的。有没有可行的方法来保存转换一个键入上述任何数据类型和背部？
But I'm trying to take it one step further - can I save a Type in an enum? I know you can save enums as a specific type (link: http://msdn.microsoft.com/en-us/library/cc138362.aspx), but Type isn't one of them. The current choices are byte, sbyte, short, ushort, int, uint, long, and ulong. Is there any feasible way to save a convert a Type to any of the above data types and back?
< STRONG>只要是明确的，这就是我希望我能做到的，我正在寻找一种方式来做到：
// (Assuming 'LightningPowerup', 'FirePowerup', and 'WaterPowerup' are
// all declared classes that inherit from a single base class)
public enum PowerupEffectType
{
LIGHTNING = typeof(LightningPowerup),
FIRE = typeof(FirePowerup),
WATER = typeof(WaterPowerup)
}
有没有办法做到这一点，还是我只是过于复杂的解决方案，以一个已经完成了99％的问题吗？
Is there any way to do this, or am I just overcomplicating a solution to a problem that's already 99% complete?
在此先感谢！
推荐答案
您不能做到这一点作为的值的枚举的，但你可以的在的属性指定它：
You can't do it as the value of an enum, but you could specify it in an attribute:
using System;
using System.Runtime.CompilerServices;
[AttributeUsage(AttributeTargets.Field)]
public class EffectTypeAttribute : Attribute
{
public Type Type { get; private set; }
public EffectTypeAttribute(Type type)
{
this.Type = type;
}
}
public class LightningPowerup {}
public class FirePowerup {}
public class WaterPowerup {}
public enum PowerupEffectType
{
[EffectType(typeof(LightningPowerup))]
Lightning,
[EffectType(typeof(FirePowerup))]
Fire,
[EffectType(typeof(WaterPowerup))]
Water
}
您可以再在执行时与反思中提取的属性值。不过，我的亲自的只是创建一个字典：
You can then extract those attribute values at execution time with reflection. However, I would personally just create a dictionary:
private static Dictionary<PowerupEffectType, Type> EffectTypeMapping =
new Dictionary<PowerupEffectType, Type>
{
{ PowerupEffectType.Lightning, typeof(LightningPowerup) },
{ PowerupEffectType.Fire, typeof(FirePowerup) },
{ PowerupEffectType.Water, typeof(WaterPowerup) }
};
没有需要有一个特殊的属性，无需提取与繁琐的反射代码的值。
No need for a special attribute, no need to extract the values with fiddly reflection code.
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