static void Main(string[] args) { List<Customer> cust = new List<Customer>() { new Customer{first="11",last="a1",ID="1",City="chian"}, new Customer{first="22",last="a2",ID="2",City="guangzhou"}, new Customer{first="33",last="a3",ID="3",City="beijing"}, new Customer{first="44",last="a4",ID="4",City="shanghai"} }; //linq寫法 //IEnumerable<Customer> cus = from cu in cust where cu.City == "beijing" select cu; //lamada寫法 IEnumerable<Customer> cus = cust.Where(p => p.City == "beijing").Select(p => p); foreach (Customer item in cus) { Console.WriteLine(item.first + "," + item.last); } Console.ReadKey(); } } class Customer { public string first { get; set; } public string last { get; set; } public string ID { get; set; } public string City { get; set; } }