Roles.RemoveUserFromRole Method (String, String)

 

Removes the specified user from the specified role.

Namespace:   System.Web.Security
Assembly:  System.Web (in System.Web.dll)

Public Shared Sub RemoveUserFromRole (
	username As String,
	roleName As String
)

Parameters

username
Type: System.String

The user to remove from the specified role.

roleName
Type: System.String

The role to remove the specified user from.

Exception Condition
System.ArgumentNullException

roleName is null.

-or-

username is null.

System.ArgumentException

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

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

System.Configuration.Provider.ProviderException

Role management is not enabled.

The RemoveUserFromRole method calls the default role provider to remove the specified user from the specified role at the data source.

The following code example removes a user from a role. For an example of a Web.config file that enables role management, see Roles.


<%@ Page Language="VB" %>

<%@ 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">

  Dim rolesArray() As String
  Dim users As MembershipUserCollection
  Dim usersInRole() As String

  Public Sub Page_Load()

    Msg.Text = ""

    If Not IsPostBack Then
      ' Bind roles to ListBox.

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

      ' Bind users to ListBox.

      users = Membership.GetAllUsers()
      UsersListBox.DataSource = users
      UsersListBox.DataBind()
    End If

    If Not RolesListBox.SelectedItem Is Nothing Then
      ' Show users in role. Bind user list to GridView.

      usersInRole = Roles.GetUsersInRole(RolesListBox.SelectedItem.Value)
      UsersInRoleGrid.DataSource = usersInRole
      UsersInRoleGrid.DataBind()
    End If

  End Sub


  Public Sub AddUsers_OnClick(ByVal sender As Object, ByVal args As EventArgs)

    ' Verify that a role is selected.

    If RolesListBox.SelectedItem Is Nothing Then
      Msg.Text = "Please select a role."
      Return
    End If


    ' Verify that at least one user is selected.

    If UsersListBox.SelectedItem Is Nothing Then
      Msg.Text = "Please select one or more users."
      Return
    End If


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

    Dim newusers(UsersListBox.GetSelectedIndices().Length - 1) As String

    For i As Integer = 0 To newusers.Length - 1
      newusers(i) = UsersListBox.Items(UsersListBox.GetSelectedIndices(i)).Value
    Next


    ' 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 e As Exception
      Msg.Text = e.Message
    End Try

  End Sub


  Public Sub UsersInRoleGrid_RemoveFromRole(ByVal sender As Object, ByVal args As GridViewCommandEventArgs)

    ' Get the selected user name to remove.

    Dim index As Integer = Convert.ToInt32(args.CommandArgument)

    Dim username As String = (CType(UsersInRoleGrid.Rows(index).Cells(0).Controls(0), DataBoundLiteralControl)).Text


    ' Remove the user from the selected role.

    Try
      Roles.RemoveUserFromRole(username, RolesListBox.SelectedItem.Value)
    Catch e As Exception
      Msg.Text = "An exception of type " & e.GetType().ToString() & _
                 " was encountered removing the user from the role."
    End Try

    ' Re-bind users in role to GridView.

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

  End Sub



</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>

.NET Framework
Available since 2.0
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