class Program
    {
        static void Main(string[] args)
        {

        }
        //这个方法用Lambda可以编写吗？要返回一个int类型，对Lambda各种不懂。
        static int Cash()
        {
            int price = 0;
            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}
            };
            for (int i = 0; i < pros.Count; i++)
            {
                if (pros[i].TypeName == "类型1")
                {
                    price = Convert.ToInt32(pros[i].Price);
                }
            }
            return price;
        }
    }
    class Product
    {
        public string TypeName;
        public string Type;
        public double Price;
    }

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}
            }.Where(x=>x.TypeName=="类型1").Select(x=>int.Parse(x.Price)).First();

------解决方案--------------------
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}
           }.Where(x=>x.TypeName=="类型1").Select(x=>new{int.Parse(x.Price)}).First();


------解决方案--------------------

C# code

        struct Product
        {
            public string TypeName;
            public string Type;
            public float Price;
        }
        private void button10_Click(object sender, EventArgs e)
        {
            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1").Select(x => new { x.Price });
        }

------解决方案--------------------

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 query=pros.Where(x=>x.TypeName=="类型1").Select(x=>Convert.ToInt32(x.Price)).DefaultOrFirst();