Typesafe枚举或属性枚举?

时间:2013-12-17 17:42:12

标签: c# enums attributes typesafe

我的第一个方法看起来非常好用,直到我遇到运行时错误我不知道如何在var name = ((LCData)attributes[0]).Name;解决索引超出范围的问题。实际上我只是复制了我在Getting attributes of Enum's value找到的代码,所以我并不是百分之百确定它实际上做了什么。因此,当以下代码不起作用时,我转向另一个解决方案。

public enum Identification : ushort

{

    [LCAttribute("IMG_BG01_Greens")]
    BG01_Greens = 0,

    [LCAttribute("Rabbit", "IMG_E01_Rabbit")]
    ENEMY_E01_Rabbit = 2000,
}

public static class Enums
{
    public static LCData GetInfo(Identification id)
    {
        var type = typeof(Identification);
        var memInfo = type.GetMember(id.ToString());
        var attributes = memInfo[0].GetCustomAttributes(typeof(LCData), false);
        var name = ((LCData)attributes[0]).Name;
        var tex = ((LCData)attributes[0]).Texture;

        LCData data;
        data.Name = name;
        data.Texture = tex;
        return data;
    }
}

public struct LCData
{
    public string Name;
    public string Texture;

    public LCData(Identification id)
    {
        this = Enums.GetInfo(id);
    }
}

public class LCAttribute : System.Attribute
{
    private string _Name;
    public string Name
    {
        get
        {
            return _Name;
        }
    }

    private string _Texture;
    public string Texture
    {
        get
        {
            return _Texture;
        }
    }

    public LCAttribute(string texture)
    {
        _Texture = texture;
    }

    public LCAttribute(string name, string texture)
    {
        _Name = name;
        _Texture = texture;
    }
}

其次,我尝试了类型安全的枚举方法。这有两个致命的弱点,我无法找到解决方案:

1)我无法获得循环操作的可用枚举条目列表。

2)我无法通过身份证号码获取相应的枚举条目。

public sealed class Identification
{

    private readonly ushort _ID;
    private readonly string _Name;
    private readonly string _Tex;

    public static readonly Identification BG01_Greens = new Identification(0, "IMG_BG01_Greens");
    public static readonly Identification ENEMY_E01_Rabbit = new Identification(2000, "Rabbit", "IMG_E01_Rabbit");

    private Identification(ushort id, string tex)
    {
        _ID = id;
        _Tex = tex;
    }

    private Identification(ushort id, string name, string tex)
    {
        _ID = id;
        _Name = name;
        _Tex = tex;
    }
    public ushort ID { get { return _ID; } }
    public string Name { get { return _Name; } }
    public string Texture { get { return _Tex; } }
}

我该怎么办?为什么我的第一个解决方案不起作用?

1 个答案:

答案 0 :(得分:0)

您感到困惑LCDataLCAttriubte。由于LCAttribute是有效属性,但您尝试使用LCData作为属性。 (顺便说一句,你可能不需要两种不同的类型......但我忍受你)。

这是修改后的代码:

public enum Identification : ushort
{
    [LCAttribute("IMG_BG01_Greens")] //Look the type of the attributes is LCAttribute
    BG01_Greens = 0,

    [LCAttribute("Rabbit", "IMG_E01_Rabbit")]
    ENEMY_E01_Rabbit = 2000,
}

public static class Enums
{
    public static LCData GetInfo(Identification id)
    {
        var type = typeof(Identification);
        var memInfo = type.GetMember(id.ToString());
        //this will return an array of LCAttributes
        var attributes = memInfo[0].GetCustomAttributes(typeof(LCAttribute), false);
        //I tell you they are LCAttribute not LCData
        var name = ((LCAttribute)attributes[0]).Name;
        var tex = ((LCAttribute)attributes[0]).Texture;
        //If the above were an LCData why would create a new one here? [Rethorical]
        LCData data;
        data.Name = name;
        data.Texture = tex;
        return data;
    }
}

注意:对于altenatives方法,可能会对此方法有所了解,您可以看到my answer to How do you make an 'enum' that has data tied to it?。您在此处使用的方法列在“自定义属性”下。