Public Shared ReadOnly Property Provider As RoleProvider
Dim value As RoleProvider value = Roles.Provider
public static RoleProvider Provider { get; }
public: static property RoleProvider^ Provider { RoleProvider^ get (); }
/** @property */ public static RoleProvider get_Provider ()
public static function get Provider () : RoleProvider
System.Configuration.Provider.ProviderException
未启用角色管理。
Provider 属性使您能够直接引用应用程序的默认角色提供程序。这通常用于访问角色提供程序的不属于 RoleProvider 抽象类的自定义成员。
例如，WindowsTokenRoleProvider 类包含 IsUserInRole 方法的重载，使您能够通过使用 WindowsBuiltInRole 枚举值来确定用户是否属于常见的 Windows 角色。对应用程序的 WindowsTokenRoleProvider 类的引用可通过使用 Provider 属性来获得，并且可将此引用强制转换为 WindowsTokenRoleProvider，以便引用 IsUserInRole 重载。
如果为应用程序配置了多个角色提供程序，则可以使用 Providers 集合访问不同的角色提供程序。
下面的代码示例演示的是：将默认角色提供程序强制转换为 WindowsTokenRoleProvider，然后在允许当前登录的用户查看应用程序的角色设置之前，检查其角色是否为 Administrators。有关启用角色管理的 Web.config 文件的示例，请参见 WindowsTokenRoleProvider。
<%@ Page Language="VB" %> <%@ Import Namespace="System.Web.Security" %> <script runat="server"> Dim rolesArray() As String Public Sub Page_Load() Msg.Text = "" Dim provider As WindowsTokenRoleProvider = CType(Roles.Provider, WindowsTokenRoleProvider) If Not provider.IsUserInRole(User.Identity.Name, _ System.Security.Principal.WindowsBuiltInRole.Administrator) Then Msg.Text = "You are not authorized to view user roles." Return End If ' Bind roles to GridView. Try rolesArray = Roles.GetRolesForUser(User.Identity.Name) Catch e As HttpException Msg.Text = "There is no current logged on user. Role membership cannot be verified." Return End Try UserRolesGrid.DataSource = rolesArray UserRolesGrid.DataBind() UserRolesGrid.Columns(0).HeaderText = "Roles for " & User.Identity.Name End Sub </script> <html> <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:GridView runat="server" CellPadding="4" id="UserRolesGrid" AutoGenerateColumns="false" Gridlines="None" CellSpacing="0" > <HeaderStyle BackColor="navy" ForeColor="white" /> <Columns> <asp:TemplateField HeaderText="Roles" runat="server" > <ItemTemplate> <%# Container.DataItem.ToString() %> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView></td> </tr> </table> </form> </body> </html>
<%@ Page Language="C#" %> <%@ Import Namespace="System.Web.Security" %> <%@ Import Namespace="System.Security.Principal" %> <script runat="server"> string[] rolesArray; public void Page_Load() { Msg.Text = ""; WindowsPrincipal p = (WindowsPrincipal)System.Threading.Thread.CurrentPrincipal; if (!p.IsInRole(WindowsBuiltInRole.Administrator)) { Msg.Text = "You are not authorized to view user roles."; return; } // Bind roles to GridView. try { rolesArray = Roles.GetRolesForUser(User.Identity.Name); } catch (HttpException e) { Msg.Text = "There is no current logged on user. Role membership cannot be verified."; return; } UserRolesGrid.DataSource = rolesArray; UserRolesGrid.DataBind(); UserRolesGrid.Columns[0].HeaderText = "Roles for " + User.Identity.Name; } </script> <html> <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:GridView runat="server" CellPadding="4" id="UserRolesGrid" AutoGenerateColumns="false" Gridlines="None" CellSpacing="0" > <HeaderStyle BackColor="navy" ForeColor="white" /> <Columns> <asp:TemplateField HeaderText="Roles" runat="server" > <ItemTemplate> <%# Container.DataItem.ToString() %> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView></td> </tr> </table> </form> </body> </html>
Windows 98、Windows 2000 SP4、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。