static void Main(string[] args) {     Employee employee = new Employee();     //设置初始值     List<Employee> employeeList = new List<Employee>();     employeeList.Add(new Employee() { EmpId = "001", EmpName = "Tony" });     employeeList.Add(new Employee() { EmpId = "002", EmpName = "Mack" });     employeeList.Add(new Employee() { EmpId = "003", EmpName = "Jon" });     employeeList.Add(new Employee() { EmpId = "004", EmpName = "Dawei" });     employeeList.Add(new Employee() { EmpId = "005", EmpName = "Jack" });     employeeList.Add(new Employee() { EmpId = "006", EmpName = "Abby" });     employeeList.Add(new Employee() { EmpId = "007", EmpName = "Carrie" });     //指定置前排序元素     List<Employee> toSortList = new List<Employee>();     toSortList.Add(new Employee() { EmpId = "003", EmpName = "Jon" });     toSortList.Add(new Employee() { EmpId = "005", EmpName = "Jack" });     toSortList.Add(new Employee() { EmpId = "007", EmpName = "Carrie" });     //自定义 排序委托     employeeList.Sort((Employee x, Employee y) => (toSortList.Count(e => e.EmpId == y.EmpId) - toSortList.Count(e => e.EmpId == x.EmpId))); } public class Employee {     public string EmpId     {         get;         set;     }     public string EmpName     {         get;         set;     } }