通过

RolePrincipal.IsInRole(String) 方法

  • 参考

定义

命名空间:
System.Web.Security
程序集:
System.Web.dll

获取一个值，该值指示由 RolePrincipal 表示的用户是否扮演指定的角色。

public:
 virtual bool IsInRole(System::String ^ role);
public:
 override bool IsInRole(System::String ^ role);
public bool IsInRole (string role);
public override bool IsInRole (string role);
abstract member IsInRole : string -> bool
override this.IsInRole : string -> bool
override this.IsInRole : string -> bool
Public Function IsInRole (role As String) As Boolean
Public Overrides Function IsInRole (role As String) As Boolean

参数

role
String

要搜索的角色。

返回

Boolean

如果由 RolePrincipal 表示的用户扮演指定的角色，则为 true；否则为 false。

实现

IsInRole(String)

例外

ProviderException

Identity 属性为 null。

示例

下面的代码示例先检查登录用户是否为管理员角色，然后允许用户查看用户角色。

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

string[] rolesArray;
MembershipUserCollection users;

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

  if (!User.IsInRole("Administrators"))
  {
    Msg.Text = "You are not authorized to view user roles.";
    UsersListBox.Visible = false;
    return;
  }

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

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


  // If a user is selected, show the roles for the selected user.

  if (UsersListBox.SelectedItem != null)
  {
    // Bind roles to GridView.

    rolesArray = Roles.GetRolesForUser(UsersListBox.SelectedItem.Value);
    UserRolesGrid.DataSource = rolesArray;
    UserRolesGrid.DataBind();

    UserRolesGrid.Columns[0].HeaderText = "Roles for " + UsersListBox.SelectedItem.Value;
  }
}

</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>

<%@ 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>

注解

IsInRole 首先检查 IsRoleListCached 属性以确定当前用户的角色名称缓存列表是否可用。 IsRoleListCached如果 属性为 true，则会检查缓存列表以查找指定角色。 IsInRole如果 方法在缓存列表中找到指定角色，则返回 true。

如果未 IsInRole 找到指定角色，它将调用 GetRolesForUser 默认 Provider 实例的 方法，以确定用户名是否与数据源中配置 ApplicationName 值的角色相关联。

适用于

另请参阅