我在发现.Any()之前使用的技术:

var hasJohn = (from customer in list
      where customer.FirstName == "John"
      select customer).FirstOrDefault() != null;

下面这个问题(如何找到一个可能有多个名字的客户)的一个选项:

List<string> names = new List<string>{ "John", "Max", "Pete" };
bool has = customers.Any(cus => names.Contains(cus.FirstName));

或者从CSV的相似列表中检索客户

string input = "John,Max,Pete";
List<string> names = input.Split(',').ToList();
customer = customers.FirstOrDefault(cus => names.Contains(cus.FirstName));

LINQ定义了一个非常适合解决这个问题的扩展方法:

using System.Linq;
...
    bool has = list.Any(cus => cus.FirstName == "John");

确保你引用System.Core.dll，那是LINQ所在的地方。

试试这个，我希望它能帮助你。

 if (lstCustumers.Any(cus => cus.Firstname == "John"))
 {
     //TODO CODE
 }

customerList.Any(x=>x.Firstname == "John")

List<Customer> list = ...;
Customer john = list.SingleOrDefault(customer => customer.Firstname == "John");

如果不存在名字为“john”的客户，则john将为空。