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Roles.GetUsersInRole(String) Method

  • Reference

Definition

Namespace:
System.Web.Security
Assembly:
System.Web.dll

Gets a list of users in the specified role.

public static string[] GetUsersInRole(string roleName);

Parameters

roleName
String

The role to get the list of users for.

Returns

String[]

A string array containing the names of all the users who are members of the specified role.

Exceptions

ArgumentNullException

roleName is null.

ArgumentException

roleName is an empty string or contains a comma (,).

ProviderException

Role management is not enabled.

Examples

The following code example uses the GetUsersInRole method to get a list of the users in a particular role and binds the results to a GridView control. For an example of a Web.config file that enables role management, see Roles.


<%@ Page Language="C#" %>

<%@ Import Namespace="System.Web.Security" %>
<%@ Import Namespace="System.Web.UI" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  string[] rolesArray;
  MembershipUserCollection users;
  string[] usersInRole;

  public void Page_Load()
  {
    Msg.Text = "";

    if (!IsPostBack)
    {
      // Bind roles to ListBox.

      rolesArray = Roles.GetAllRoles();
      RolesListBox.DataSource = rolesArray;
      RolesListBox.DataBind();

      // Bind users to ListBox.

      users = Membership.GetAllUsers();
      UsersListBox.DataSource = users;
      UsersListBox.DataBind();
    }

    if (RolesListBox.SelectedItem != null)
    {
      // Show users in role. Bind user list to GridView.

      usersInRole = Roles.GetUsersInRole(RolesListBox.SelectedItem.Value);
      UsersInRoleGrid.DataSource = usersInRole;
      UsersInRoleGrid.DataBind();
    }
  }


  public void AddUsers_OnClick(object sender, EventArgs args)
  {
    // Verify that a role is selected.

    if (RolesListBox.SelectedItem == null)
    {
      Msg.Text = "Please select a role.";
      return;
    }


    // Verify that at least one user is selected.

    if (UsersListBox.SelectedItem == null)
    {
      Msg.Text = "Please select one or more users.";
      return;
    }


    // Create list of users to be added to the selected role.

    string[] newusers = new string[UsersListBox.GetSelectedIndices().Length];

    for (int i = 0; i < newusers.Length; i++)
    {
      newusers[i] = UsersListBox.Items[UsersListBox.GetSelectedIndices()[i]].Value;
    }


    // Add the users to the selected role.

    try
    {
      Roles.AddUsersToRole(newusers, RolesListBox.SelectedItem.Value);

      // Re-bind users in role to GridView.

      usersInRole = Roles.GetUsersInRole(RolesListBox.SelectedItem.Value);
      UsersInRoleGrid.DataSource = usersInRole;
      UsersInRoleGrid.DataBind();
    }
    catch (Exception e)
    {
      Msg.Text = e.Message;
    }
  }


  public void UsersInRoleGrid_RemoveFromRole(object sender, GridViewCommandEventArgs args)
  {
    // Get the selected user name to remove.

    int index = Convert.ToInt32(args.CommandArgument);

    string username = ((DataBoundLiteralControl)UsersInRoleGrid.Rows[index].Cells[0].Controls[0]).Text;


    // Remove the user from the selected role.

    try
    {
      Roles.RemoveUserFromRole(username, RolesListBox.SelectedItem.Value);
    }
    catch (Exception e)
    {
      Msg.Text = "An exception of type " + e.GetType().ToString() +
                 " was encountered removing the user from the role.";
    }


    // Re-bind users in role to GridView.

    usersInRole = Roles.GetUsersInRole(RolesListBox.SelectedItem.Value);
    UsersInRoleGrid.DataSource = usersInRole;
    UsersInRoleGrid.DataBind();
  }



</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
  <title>Sample: Role Membership</title>
</head>
<body>
  <form runat="server" id="PageForm">
    <h3>
      Role Membership</h3>
    <asp:Label ID="Msg" ForeColor="maroon" runat="server" /><br />
    <table cellpadding="3" border="0">
      <tr>
        <td valign="top">
          Roles:</td>
        <td valign="top">
          <asp:ListBox ID="RolesListBox" runat="server" Rows="8" AutoPostBack="true" /></td>
        <td valign="top">
          Users:</td>
        <td valign="top">
          <asp:ListBox ID="UsersListBox" DataTextField="Username" Rows="8" SelectionMode="Multiple"
            runat="server" /></td>
        <td valign="top">
          <asp:Button Text="Add User(s) to Role" ID="AddUsersButton" runat="server" OnClick="AddUsers_OnClick" /></td>
      </tr>
      <tr>
        <td valign="top">
          Users In Role:</td>
        <td valign="top">
          <asp:GridView runat="server" CellPadding="4" ID="UsersInRoleGrid" AutoGenerateColumns="false"
            GridLines="None" CellSpacing="0" OnRowCommand="UsersInRoleGrid_RemoveFromRole">
            <HeaderStyle BackColor="navy" ForeColor="white" />
            <Columns>
              <asp:TemplateField HeaderText="User Name" >
                <ItemTemplate>
                  <%# Container.DataItem.ToString() %>
                </ItemTemplate>
              </asp:TemplateField>
              <asp:ButtonField Text="Remove From Role" ButtonType="Link" />
            </Columns>
          </asp:GridView>
        </td>
      </tr>
    </table>
  </form>
</body>
</html>

Remarks

The GetUsersInRole method calls the GetUsersInRole method of the default role provider to retrieve the user names associated with a role from the data source. Only the roles for the application that is specified in the ApplicationName property are retrieved.

Applies to

Product Versions
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also