AuthorizationStoreRoleProvider.RoleExists(String) 方法

定义

获取一个值,该值指示指定角色名是否已存在于授权管理器策略存储区中。

public:
 override bool RoleExists(System::String ^ roleName);
public override bool RoleExists (string roleName);
override this.RoleExists : string -> bool
Public Overrides Function RoleExists (roleName As String) As Boolean

参数

roleName
String

要在授权管理器策略存储区中搜索的角色的名称。

返回

如果角色名已存在于授权管理器策略存储区中,则为 true;否则为 false

例外

roleNamenull

roleName 是一个空字符串。

- 或 -

roleName 包含一个逗号。

未找到已配置的 applicationName

- 或 -

未找到已配置的 scopeName

- 或 -

服务器上没有安装身份验证管理器运行时。

connectionStringName 特性引用了一个指向不存在的文件的连接字符串。

AuthorizationStoreRoleProvider 实例使用基于文件的策略存储进行配置,且当前的信任级别不允许对文件进行读访问。

示例

下面的代码示例使用 RoleExists 方法确定角色名称在创建角色之前是否已存在。 有关启用角色管理的 Web.config 文件的示例,请参阅 AuthorizationStoreRoleProvider

<%@ 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;

public void Page_Load(object sender, EventArgs args)
{
  if (!IsPostBack)
  {
    // Bind roles to GridView.

    rolesArray = Roles.GetAllRoles();
    RolesGrid.DataSource = rolesArray;
    RolesGrid.DataBind();
  }
}

public void CreateRole_OnClick(object sender, EventArgs args)
{
  string createRole = RoleTextBox.Text;

  try
  {
    if (Roles.RoleExists(createRole))
    {
      Msg.Text = "Role '" + Server.HtmlEncode(createRole) + "' already exists. Please specify a different role name.";
      return;
    }

    Roles.CreateRole(createRole);

    Msg.Text = "Role '" + Server.HtmlEncode(createRole) + "' created.";

    // Re-bind roles to GridView.

    rolesArray = Roles.GetAllRoles();
    RolesGrid.DataSource = rolesArray;
    RolesGrid.DataBind();
  }
  catch (Exception e)
  {
    Msg.Text = "Role '" + Server.HtmlEncode(createRole) + "' <u>not</u> created.";
    Response.Write(e.ToString());
  }

}

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Sample: Create Role</title>
</head>
<body>

<form runat="server" id="PageForm">
  <h3>Create a Role</h3>

  <asp:Label id="Msg" ForeColor="maroon" runat="server" /><br />

  Role name: 

  <asp:TextBox id="RoleTextBox" runat="server" />

  <asp:Button Text="Create Role" id="CreateRoleButton"
              runat="server" OnClick="CreateRole_OnClick" />

  <br />

  <asp:GridView runat="server" CellPadding="2" id="RolesGrid" 
                Gridlines="Both" CellSpacing="2" AutoGenerateColumns="false" >
    <HeaderStyle BackColor="navy" ForeColor="white" />
    <Columns>
      <asp:TemplateField HeaderText="Roles" >
        <ItemTemplate>
          <%# Container.DataItem.ToString() %>
        </ItemTemplate>
      </asp:TemplateField>
    </Columns>
   </asp:GridView>
</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

Public Sub Page_Load(sender As Object, args As EventArgs)

  If Not IsPostBack Then
    ' Bind roles to GridView.

    rolesArray = Roles.GetAllRoles()
    RolesGrid.DataSource = rolesArray
    RolesGrid.DataBind()
  End If

End Sub

Public Sub CreateRole_OnClick(sender As Object, args As EventArgs)

  Dim createRole As String = RoleTextBox.Text

  Try
    If Roles.RoleExists(createRole) Then
      Msg.Text = "Role '" & Server.HtmlEncode(createRole) & "' already exists. Please specify a different role name."
      Return
    End If

    Roles.CreateRole(createRole)

    Msg.Text = "Role '" & Server.HtmlEncode(createRole) & "' created."

    ' Re-bind roles to GridView.

    rolesArray = Roles.GetAllRoles()
    RolesGrid.DataSource = rolesArray
    RolesGrid.DataBind()
  Catch
    Msg.Text = "Role '" & Server.HtmlEncode(createRole) & "' <u>not</u> created."
  End Try

End Sub

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Sample: Create Role</title>
</head>
<body>

<form runat="server" id="PageForm">
  <h3>Create a Role</h3>

  <asp:Label id="Msg" ForeColor="maroon" runat="server" /><br />

  Role name: 

  <asp:TextBox id="RoleTextBox" runat="server" />

  <asp:Button Text="Create Role" id="CreateRoleButton"
              runat="server" OnClick="CreateRole_OnClick" />

  <br />

  <asp:GridView runat="server" CellPadding="2" id="RolesGrid" 
                Gridlines="Both" CellSpacing="2" AutoGenerateColumns="false" >
    <HeaderStyle BackColor="navy" ForeColor="white" />
    <Columns>
      <asp:TemplateField HeaderText="Roles" >
        <ItemTemplate>
          <%# Container.DataItem.ToString() %>
        </ItemTemplate>
      </asp:TemplateField>
    </Columns>
   </asp:GridView>
</form>

</body>
</html>

注解

方法 RoleExistsRoles 类调用,以确定 ASP.NET 应用程序的配置文件 (Web.config) 中指定的授权管理器数据存储中是否存在角色名称。

适用于

另请参阅