求Lamba表达式

C# code

    class Program    {        static void Main(string[] args)        {        }        // 求Lambda表达式，返回一个string类型。        static string Cash()        {            string typeInfo = string.Empty;            List<Product> pros = new List<Product>()            {                new Product(){TypeName="类型1",Type="1",Price=20},                new Product(){TypeName="类型2",Type="1",Price=24},                new Product(){TypeName="类型3",Type="2",Price=12}            };            foreach (var p in pros)            {                if (p.TypeName == "类型2")                {                    switch (p.Type)                    {                        case "1": typeInfo = "型号1"; break;                        case "2": typeInfo = "型号2"; break;                    }                }            }            return typeInfo;        }    }    struct Product    {        public string TypeName;        public string Type;        public double Price;    }

C# code

  List<Product> pros = new List<Product>()            {                new Product(){TypeName="类型1",Type="1",Price=20},                new Product(){TypeName="类型2",Type="1",Price=24},                new Product(){TypeName="类型3",Type="2",Price=12}            };            var v = pros.Where(x => x.TypeName == "类型2").Select(x =>x.Type=="1"? 型号1:型号2);
[解决办法]


C# code
        static string Cash()        {            Dictionary<string, string> dict = new Dictionary<string, string>();            dict.Add("1", "类型1");            dict.Add("2", "类型2");            List<Product> pros = new List<Product>()            {                new Product(){TypeName="类型1",Type="1",Price=20},                new Product(){TypeName="类型2",Type="1",Price=24},                new Product(){TypeName="类型3",Type="2",Price=12}            };            var query = (from x in pros                        join y in dict on x.TypeName equals y.Value into j                        select j.Key).Last();            return query;        }