Recursively get all users in a group in Active Directory C#

   1:  using System;

   2:  using System.Collections.Generic;

   3:  using System.ComponentModel;

   4:  using System.Data;

   5:  using System.Drawing;

   6:  using System.Linq;

   7:  using System.Text;

   8:  using System.Windows.Forms;

   9:  using System;

  10:  using System.DirectoryServices;

  11:  using System.Collections.Generic;

  12:  using System.DirectoryServices.AccountManagement;

  13:   

  14:  namespace RecurseUsersInGroups

  15:  {

  16:      public partial class FormGroups : Form

  17:      {

  18:   

  19:          StringBuilder _builder = new StringBuilder();

  20:   

  21:          public FormGroups()

  22:          {

  23:              InitializeComponent();

  24:          }

  25:   

  26:          private void buttonGetAllUsers_Click(object sender, EventArgs e)

  27:          {

  28:              try

  29:              {

  30:                  textBoxUsers.Clear();

  31:                  _builder.Clear();

  32:   

  33:                  PrincipalContext ctx = new PrincipalContext(ContextType.Domain, textBoxDomain.Text);

  34:                  GroupPrincipal grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.Name, textBoxADGroup.Text);

  35:   

  36:                  if (grp != null)

  37:                  {

  38:                      foreach (Principal p in grp.GetMembers(true))

  39:                      {

  40:   

  41:                          if (!_builder.ToString().Contains(p.SamAccountName))

  42:                          {

  43:                              _builder.Append(p.SamAccountName);

  44:                              _builder.Append("; ");

  45:                          }

  46:                      }

  47:   

  48:                      textBoxUsers.Text = _builder.ToString();

  49:   

  50:                      grp.Dispose();

  51:                      ctx.Dispose();

  52:   

  53:                  }

  54:                  else

  55:                  {

  56:                      MessageBox.Show("\nWe did not find that group in that domain, perhaps the group resides in a different domain?");

  57:                  }

  58:              }

  59:              catch (System.Exception)

  60:              {

  61:   

  62:                  MessageBox.Show("\nWe did not find that group in that domain, perhaps the group resides in a different domain?");

  63:              }

  64:             

  65:   

  66:   

  67:          }

  68:   

  69:   

  70:   

  71:      }

  72:  }