Roles.RemoveUserFromRoles Method (String, String())

 

Removes the specified user from the specified roles.

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

Public Shared Sub RemoveUserFromRoles (
	username As String,
	roleNames As String()
)

Parameters

username
Type: System.String

The user to remove from the specified roles.

roleNames
Type: System.String()

A string array of role names to remove the specified user from.

Exception Condition
System.ArgumentNullException

One of the roles in roleNames is null.

-or-

username is null.

System.ArgumentException

One of the roles in roleNames is an empty string or contains a comma (,).

-or-

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

-or-

roleNames contains a duplicate element.

System.Configuration.Provider.ProviderException

Role management is not enabled.

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

If the application is configured to use the SqlRoleProvider class, the database updates that are performed during the call to the RemoveUserFromRoles method are made within a transaction. If an error is encountered, such as a user name that is not in a specified role, the transaction is rolled back and no updates are performed.

The following code example uses the RemoveUserFromRoles method to remove a user from one or more roles. 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

Public Sub Page_Load()
  Msg.Text = ""

  If Not IsPostBack Then
    ' Bind roles to ListBox.

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

Public Sub UsersListBox_OnSelectedIndexChanged(sender As Object, args As EventArgs)
  ' Bind users to ListBox.

  rolesArray = Roles.GetRolesForUser(UsersListBox.SelectedItem.Value)
  RolesListBox.DataSource = rolesArray
  RolesListBox.DataBind()
End Sub

Public Sub RemoveUser_OnClick(sender As Object, args As EventArgs)
  ' Verify that at least a user and at least one role are selected.

  If UsersListBox.SelectedItem Is Nothing Then
    Msg.Text = "Please select a user."
    Return
  End If

  Dim role_indices() As Integer = RolesListBox.GetSelectedIndices()

  If role_indices.Length = 0 Then
    Msg.Text = "Please select one or more roles."
    Return
  End If


  ' Create list of roles to be remove the selected user from.

  Dim rolesList(role_indices.Length - 1) As String

  For i As Integer = 0 To  rolesList.Length - 1
    rolesList(i) = RolesListBox.Items(role_indices(i)).Value
  Next


  ' Remove the user to the selected roles.

  Try
    Roles.RemoveUserFromRoles(UsersListBox.SelectedItem.Value, rolesList)  
    Msg.Text = "User removed from Role(s)."

    ' Rebind roles to ListBox.

    rolesArray = Roles.GetRolesForUser(UsersListBox.SelectedItem.Value)
    RolesListBox.DataSource = rolesArray
    RolesListBox.DataBind()
  Catch e As HttpException
    Msg.Text = e.Message
  End Try
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">Users:</td>
      <td valign="top"><asp:ListBox id="UsersListBox" Rows="8" DataTextField="Username" 
                                    OnSelectedIndexChanged="UsersListBox_OnSelectedIndexChanged" 
                                    AutoPostBack="true" runat="server" /></td>
      <td valign="top">Roles:</td>
      <td valign="top"><asp:ListBox id="RolesListBox" SelectionMode="Multiple" 
                                    runat="server" Rows="8" /></td>
      <td valign="top"><asp:Button Text="Remove User from Roles" id="RemoveUserButton"
                                   runat="server" OnClick="RemoveUser_OnClick" /></td>
    </tr>
  </table>
</form>

</body>
</html>

.NET Framework
Available since 2.0
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