RolePrincipal.IsInRole Method (String)
Gets a value indicating whether the user represented by the RolePrincipal is in the specified role.
Assembly: System.Web (in System.Web.dll)
Parameters
- role
-
Type:
System.String
The role to search for.
Return Value
Type: System.Booleantrue if user represented by the RolePrincipal is in the specified role; otherwise, false.
Implements
IPrincipal.IsInRole(String)| Exception | Condition |
|---|---|
| ProviderException | The Identity property is null. |
IsInRole first checks the IsRoleListCached property to determine whether a cached list of role names for the current user is available. If the IsRoleListCached property is true, the cached list is checked for the specified role. If the IsInRole method finds the specified role in the cached list, it returns true.
If IsInRole does not find the specified role, it calls the GetRolesForUser method of the default Provider instance to determine whether the user name is associated with a role from the data source for the configured ApplicationName value.
The following code example checks to see whether the logged-on user is in the Administrators role before allowing the user to view user roles.
<%@ Page Language="VB" %> <%@ Import Namespace="System.Web.Security" %> <!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 User.IsInRole("Administrators") Then Msg.Text = "You are not authorized to view user roles." UsersListBox.Visible = False Return End If If Not IsPostBack Then ' Bind users to ListBox. users = Membership.GetAllUsers() UsersListBox.DataSource = users UsersListBox.DataBind() End If ' If a user is selected, show the roles for the selected user. If Not UsersListBox.SelectedItem Is Nothing Then ' Bind roles to GridView. rolesArray = Roles.GetRolesForUser(UsersListBox.SelectedItem.Value) UserRolesGrid.DataSource = rolesArray UserRolesGrid.DataBind() UserRolesGrid.Columns(0).HeaderText = "Roles for " & UsersListBox.SelectedItem.Value End If End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head> <title>Sample: View User Roles</title> </head> <body> <form runat="server" id="PageForm"> <h3>View User Roles</h3> <asp:Label id="Msg" ForeColor="maroon" runat="server" /><br /> <table border="0" cellspacing="4"> <tr> <td valign="top"><asp:ListBox id="UsersListBox" DataTextField="Username" Rows="8" AutoPostBack="true" runat="server" /></td> <td valign="top"><asp:GridView runat="server" CellPadding="4" id="UserRolesGrid" AutoGenerateColumns="false" Gridlines="None" CellSpacing="0" > <HeaderStyle BackColor="navy" ForeColor="white" /> <Columns> <asp:TemplateField HeaderText="Roles" > <ItemTemplate> <%# Container.DataItem.ToString() %> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView></td> </tr> </table> </form> </body> </html>
Available since 2.0