自动映射器枚举描述属性 [英] Automapper Enum Description Attribute

问题描述

我在从Enum Description属性进行映射时遇到困难.我一直在寻找一个有用的例子，运气很少.我知道还有一些其他示例，但我仍在为这种特殊情况而苦苦挣扎.

I'm having difficulties mapping from an Enum Description Attribute. I've been looking all over for a useful example with very little luck. I know there are some other examples out there but I'm still struggling with this particular scenario.

这是我的枚举:

public enum ResolveCodeEnum
{
    [Description("Resolved - Workaround")]
    ResolvedWorkaround = 1,
    [Description("Resolved - Permanently")]
    ResolvedPermanently = 2,
    [Description("Resolved - Unknown")]
    ResolvedUnkown = 3,
    [Description("Cannot Reproduce")]
    CannotReproduce = 4,
    [Description("Invalid")]
    Invalid = 5,
    [Description("Cancelled")]
    Cancelled = 6
}

这是我的枚举助手类:

public class EnumHelper
{
    public static string GetEnumDescription(Enum value)
    {
        FieldInfo fi = value.GetType().GetField(value.ToString());

        DescriptionAttribute[] attributes =
            (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);

        if (attributes != null && attributes.Length > 0)
            return attributes[0].Description;
        else
            return value.ToString();
    }
}

我的目标是通过Enum Description属性将源映射到目标

My goal is to map source to destination via Enum Description Attribute

这是到目前为止我的映射配置:

Here is what I have so far in my mapping configuration:

  Mapper.CreateMap<Result, Incident>()
            .ForMember(dest => dest.Status,
                opts => opts.MapFrom(src => src.state));

这里是Result类的缩写:

Here is the abbreviated Result class:

public class Result
{
    public string sys_id { get; set; }
    public string state { get; set; }
}

这是缩写的事件类:

public class Incident
{
    public string Id{ get; set; }
    public string Status{ get; set; }
}

注意:Result类的state属性是一个字符串

Note: the state property of the Result class is a string

例如:

我的目标是获得

 Incident.Status = "Resolved - Workaround"

来自

 Result.state = "1"

我一直在努力与EnumHelper类一起使用的自动映射器语法

I've been struggle with the automapper syntax to use with my EnumHelper class

如果有人可以帮助我，将不胜感激:)

If anybody can help me out on this, it would be greatly appreciated :)

推荐答案

执行此操作的两种方法:

Two ways to do this:

1. 与ResolveUsing内联:

    Mapper.CreateMap<Result, Incident>()
        .ForMember(
            dest => dest.Status,
            opt => opt.ResolveUsing(src =>
            {
                var value = (ResolveCodeEnum)Enum.Parse(
                                typeof(ResolveCodeEnum), src.state);

                return EnumHelper.GetEnumDescription(value);
            }));

带有自定义的ValueResolver:

public class EnumValueResolver : ValueResolver<Result, string>
{
    protected override string ResolveCore(Result src)
    {
        var value = (ResolveCodeEnum)Enum.Parse(typeof(ResolveCodeEnum), src.state);

        return EnumHelper.GetEnumDescription(value);    
    }
}

用法:

Mapper.CreateMap<Result, Incident>()
    .ForMember(
        dest => dest.Status,
        opt => opt.ResolveUsing<EnumValueResolver>());

我建议#2，因为它更干净.

I'd recommend #2 since it's much cleaner.

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