层级列表中的员工/经理

我有三个类。我想获得所选员工的员工层次结构。

public class Employees
{
    public int empId{ get; set; }
    public string empName { get; set; }
    public Employees(int id, string name)
    {
        empId= id;
        empName = name;
    }
}
public class EmployeeManager
{
    public int empmgr_id { get; set; }
    public int emp_id { get; set; }
    public int mgr_id{ get; set; }
    public EmployeeManager(int emid, int eid, int mid)
    {
        empmgr_id = emid;
        emp_id = eid;
        mgr_id= mid;
    }
}
public static class EmpMgrData
{
    public static IEnumerable<Employees> EmpList()
    {
        var lstEmp = new List<Employees>();
        lstEmp .Add(new Employees(1,"Emp 1"));
        lstEmp .Add(new Employees(2,"Emp 2"));
        lstEmp .Add(new Employees(3,"Emp 3"));
        lstEmp .Add(new Employees(4,"Emp 4"));
        lstEmp .Add(new Employees(5,"Emp 5"));
        lstEmp .Add(new Employees(6,"Emp 6"));
        lstEmp .Add(new Employees(7,"Emp 7"));
        lstEmp .Add(new Employees(8,"Emp 8"));
        lstEmp .Add(new Employees(9,"Emp 9"));
        lstEmp .Add(new Employees(10,"Emp 10"));
        lstEmp .Add(new Employees(11,"Emp 11"));
        lstEmp .Add(new Employees(12,"Emp 12"));
        lstEmp .Add(new Employees(13,"Emp 13"));
        lstEmp .Add(new Employees(14,"Emp 14"));
        lstEmp .Add(new Employees(15,"Emp 15"));
        lstEmp .Add(new Employees(16,"Emp 16"));
        lstEmp .Add(new Employees(17,"Emp 17"));
        lstEmp .Add(new Employees(18,"Emp 18"));
        lstEmp .Add(new Employees(19,"Emp 19"));
        lstEmp .Add(new Employees(20,"Emp 20"));
        return lstEmp ;
    }
    public static IEnumerable<EmployeeManager> EmpMgrList()
    {
        var lstEmpMgr = new List<EmployeeManager>
                                   {
                                       new EmployeeManager(1,18,19),
                                       new EmployeeManager(2,17,20),
                                       new EmployeeManager(3,19,17),
                                       new EmployeeManager(4,14,15),
                                       new EmployeeManager(5,13,15),
                                       new EmployeeManager(6,12,13),
                                       new EmployeeManager(7,9,13),
                                       new EmployeeManager(8,10,13),
                                       new EmployeeManager(9,11,13),
                                       new EmployeeManager(10,6,5), 
                                       new EmployeeManager(11,7,5), 
                                       new EmployeeManager(12,8,5), 
                                       new EmployeeManager(13,5,4), 
                                       new EmployeeManager(14,4,20), 
                                       new EmployeeManager(15,2,4), 
                                       new EmployeeManager(16,1,3), 
                                       new EmployeeManager(17,3,20)
                                   };
        return lstEmpMgr ;
    }
}
private void Form1_Load(object sender, EventArgs e)
    {
        //Displaying list of persons in the combo box
        var empList = EmpMgrData.EmpList();
        comboBox1.DataSource = empList;
        comboBox1.DisplayMember = "empName";
        comboBox1.ValueMember = "empId";
    }
 private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (!string.IsNullOrEmpty(comboBox1.DisplayMember))
        {
            listBox1.DataSource = null;
            listBox1.Items.Clear();
            var personKey = ((Employees)comboBox1.SelectedItem).empId;
            var personname = ((Employees)comboBox1.SelectedItem).empName;
            List<EmployeeManager> hierarchyDownEmployees = null;
            List<Employees> hierarchyDownEmployeesName = null;
            hierarchyDownEmployees = EmpMgrData.EmpMgrList().ToList();
            //Using an Extension method to get the hierarchy of employees for the selected person.First we find all the direct employees of selected person and  using the extension method, we will find the hierarchy                   
            List<int> hEmployees = new List<int>(hierarchyDownEmployees.GetHierarchyEmployees(personKey));
            for (int i = 0; i < hEmployees.Count; i++)
            {
                hEmployees.AddRange(hierarchyDownEmployees.GetHierarchyEmployees(hEmployees[i]).Except(hEmployees));
            }
            //Finding the EmpName of the hierarchy employees
            hierarchyDownEmployeesName = EmpMgrData.EmpList().Where(n => hEmployees.Any(s => s == n.empId)).ToList();
            //Displaying the Hierarchy Employee Names of selected person to the list box
            if (hierarchyDownEmployeesName != null && hierarchyDownEmployeesName.Count() > 0)
            {
                label2.Text = "All Employees under " + comboBox1.Text + " are: " + string.Join(", ", hEmployees);
                listBox1.DataSource = hierarchyDownEmployeesName;
                listBox1.DisplayMember = "empName";
                listBox1.ValueMember = "empId";
                listBox1.SelectedIndex = -1;
            }                
        }
    }
}
public static class Hierarchy
{
    //Extension method to get the Employee Hierarchy of the selected person
    public static IEnumerable<int> GetHierarchyEmployees(this IEnumerable<EmployeeManager> employees, int empID)
    {
        return from emp in employees
               where emp.mgr_id == empID
               select emp.emp_id ;
    }
}

当我在ComboBox中选择一个人员时，我希望根据员工/经理关系显示层次结构('down')中的员工列表，一直到没有员工向他们报告的最下面的人员。我的代码检索所选人员下的所有员工，但不按层次顺序检索。(当我从EmpList中找到员工名称时)

• 例子:
• Emp 20
• >> Emp 3
• >>>> Emp 1
• >> Emp 4
• >>>> Emp 5
• >>>>>>>> Emp 6
• >>>>>>>> Emp 7
• >>>>>>>> Emp 8
• >>>> Emp 2
• >> Emp 17
• >>>> Emp 19
• >>>> Emp 18

谢谢你的帮助!