Question

我有一个代表不同内容的ID列表。我想将这些ID显示为字符串。

例如，数字12将映射到"foo"，而13会映射到"bar"

更具体地说，我正在尝试将模型属性迁移到包含已转换字符串值的列表。这是我目前的

var model = new PaymentExclusionModel
{
    ExclusionList = response.Exclusions,
};
List<PaymentProcessorExclusionModel> list = new List<PaymentProcessorExclusionModel>();
list = response.Exclusions.Select(x => new PaymentProcessorExclusionModel
{
    // Convert
});

我知道将整数映射到字符串的值是什么，因为它是一小组值。我试图使用Dictionary<int, string>，但我收到一个错误抱怨转换int？ to int（int？来自元数据dll，我不能改变它）。

以下是代码：

var model = new PaymentExclusionModel
            {
                ExclusionList = response.Exclusions,
            };
            List<PaymentProcessorExclusionModel> list = new List<PaymentProcessorExclusionModel>();
            list = response.Exclusions.Select(x => new PaymentProcessorExclusionModel
            {
                PaymentType = dict[x.PaymentTypeId.Value]
            });

错误代码：

Error   CS0266  Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<DK.Fin.Secure.Mjolnir.Web.Models.PaymentProcessorExclusionModel>' to 'System.Collections.Generic.List<Web.Models.PaymentProcessorExclusionModel>'. An explicit conversion exists (are you missing a cast?)

Answer 1

这是一个枚举式解决方案：

public class MyType : EnumClass
{
    public static MyType FOO = new MyType(12, "Foo");
    public static MyType BAR = new MyType(13, "Bar");
    public static MyType X = new MyType(99, "X");

    [JsonConstructor]
    private MyType(int id, string name)
    {
        _id = id;
        _name = name;
    }

    public static MyType GetMyType(int id)
    {
        switch (id)
        {
            case 12: return FOO;
            case 13: return BAR;
            case 99: return X;
            default: return null;
        }
    }

    public static IEnumerable<MyType> GetMyTypes()
    {
        return new List<MyType>
        {
            FOO,
            BAR,
            X
        };
    }
}

我使用过这种类型的东西并取得了巨大的成功。我有一个扑克应用程序，在这种情况下，＆＃39; MyType＆＃39;是卡＆＃39;具有扑克牌的所有属性（套装，号码等）。

EnumClass

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MyProj.MyPath
{
    public abstract class EnumClass
    {
        protected int _id;
        protected string _name;

        public virtual int ID
        {
            get { return _id; }
        }

        public virtual string Name
        {
            get { return _name; }
        }

        public override string ToString()
        {
            return Name;
        }

        public override int GetHashCode()
        {
            return ID.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            if (obj is EnumClass)
                return ID == (obj as EnumClass).ID;

            return base.Equals(obj);
        }

        public static bool operator ==(EnumClass left, EnumClass right)
        {
            if ((left as Object) == null)
                return (right as Object) == null;

            return left.Equals(right);
        }

        public static bool operator !=(EnumClass left, EnumClass right)
        {
            if ((left as Object) == null)
                return (right as Object) != null;

            return !left.Equals(right);
        }
    }
}

Answer 2

我不知道为什么，但我相信你想在字符串和int值之间创建一个数组映射。首先，您需要使用字典

Dictionary<int, string> map = new Dictionary<int, string>();

然后只需添加您的值

map.Add(12, 'foo');
map.Add(13, 'bar');

然后基本上你所要做的就是像字典一样调用字典

list = response.Exclusions.Select(x => new PaymentProcessorExclusionModel
{
   NewId = map.ContainsKey(x) ? map[x] : "defaultkey?"
});

这显然是要走的路。尝试创建“＆＃39;”列表＆＃39;动态变量如此

var list = response.Exclusions.Select(x => new PaymentProcessorExclusionModel
        {
            PaymentType = dict[x.PaymentTypeId.Value]
        });

如何将ID值（int）映射到C＃

2 个答案: