我不确定这是否正是您想要的,但这里有一种递归方法,使用了一些linq来确保不进入无限循环:
public static IEnumerable<Employee> GetTreeForEmployeeNumber(this IEnumerable<Employee> source, int startingId) {
var result = source.Where(x => x.EmployeeId == startingId).FirstOrDefault();
if (result != null) {
var resultAsE = new [] { result };
if (!result.ManagerId.HasValue)
return resultAsE;
return resultAsE.Union(source.Except(resultAsE).GetTreeForEmployeeNumber(result.ManagerId.Value));
}
return new Employee [] { };
}
如果你已经安装了LinqPad,你可以使用以下脚本进行测试:
void Main()
{
var lst = new [] {
new Extensions.Employee{ EmployeeId = 1, Name = "A", ManagerId = null },
new Extensions.Employee{ EmployeeId = 2, Name = "B", ManagerId = null },
new Extensions.Employee{ EmployeeId = 3, Name = "C", ManagerId = 1 },
new Extensions.Employee{ EmployeeId = 4, Name = "D", ManagerId = 3 },
new Extensions.Employee{ EmployeeId = 5, Name = "E", ManagerId = 2 }
};
lst.GetTreeForEmployeeNumber(4).Dump();
}
public static class Extensions {
public class Employee {
public int EmployeeId { get; set; }
public string Name { get; set; }
public int? ManagerId { get; set; }
}
public static IEnumerable<Employee> GetTreeForEmployeeNumber(this IEnumerable<Employee> source, int startingId) {
var result = source.Where(x => x.EmployeeId == startingId).FirstOrDefault();
if (result != null) {
var resultAsE = new [] { result };
if (!result.ManagerId.HasValue)
return resultAsE;
return resultAsE.Union(source.Except(resultAsE).GetTreeForEmployeeNumber(result.ManagerId.Value));
}
return new Employee [] { };
}
}