ClientRoleProvider.GetRolesForUser(String) 方法

定义

获取指定用户所属的角色的名称。

public:
 override cli::array <System::String ^> ^ GetRolesForUser(System::String ^ username);
public override string[] GetRolesForUser (string username);
override this.GetRolesForUser : string -> string[]
Public Overrides Function GetRolesForUser (username As String) As String()

参数

username
String

要为其检索角色的用户的名称。

返回

String[]

username 属于的角色名称;如果未对用户进行身份验证,则为空数组。

例外

username Emptynull

-或-

username 不是当前经过身份验证的用户的用户名。

示例

以下示例代码演示如何使用此方法来确定用户登录名在测试角色成员身份之前是否已过期。 此代码假定所有有效用户都与一个或多个角色相关联。 在这种情况下,GetRolesForUser 方法不会为登录名已过期的以前经过身份验证的用户返回任何角色。 如果用户登录名已过期,此代码将显示登录对话框。 否则,它会调用 IsUserInRole 方法来确定用户是否处于“经理”角色。 受限代码位于未提供 PerformManagerTask 方法中。

private void AttemptManagerTask()
{
    System.Security.Principal.IIdentity identity =
        System.Threading.Thread.CurrentPrincipal.Identity;

    // Return if the authentication type is not "ClientForms". 
    // This indicates that the user is logged out.
    if (!identity.AuthenticationType.Equals("ClientForms")) return;

    try
    {
        ClientRoleProvider provider =
            (ClientRoleProvider)System.Web.Security.Roles.Provider;
        String userName = identity.Name;

        // Determine whether the user login has expired by attempting
        // to retrieve roles from the service. Call the ResetCache method
        // to ensure that the roles are retrieved from the service. If no 
        // roles are returned, then the login has expired. This assumes 
        // that every valid user has been assigned to one or more roles.
        provider.ResetCache();
        String[] roles = provider.GetRolesForUser(userName);
        if (roles.Length == 0)
        {
            MessageBox.Show(
                "Your login has expired. Please log in again to access " +
                "the roles service.", "Attempting to access user roles...");

            // Call ValidateUser with empty strings in order to 
            // display the login dialog box configured as a 
            // credentials provider.
            if (!System.Web.Security.Membership.ValidateUser(
                String.Empty, String.Empty))
            {
                MessageBox.Show("Unable to authenticate. " +
                    "Cannot retrieve user roles.", "Not logged in",
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
        }

        if (provider.IsUserInRole(userName, "manager"))
        {
            PerformManagerTask();
        }
    }
    catch (System.Net.WebException)
    {
        MessageBox.Show(
            "Unable to access the remote service. " +
            "Cannot retrieve user roles.", "Warning",
            MessageBoxButtons.OK, MessageBoxIcon.Warning);
    }
}
Private Sub AttemptManagerTask()

    Dim identity As System.Security.Principal.IIdentity = _
        System.Threading.Thread.CurrentPrincipal.Identity

    ' Return if the authentication type is not "ClientForms". 
    ' This indicates that the user is logged out.
    If Not identity.AuthenticationType.Equals("ClientForms") Then Return

    Try

        Dim provider As ClientRoleProvider = _
            CType(System.Web.Security.Roles.Provider, ClientRoleProvider)
        Dim userName As String = identity.Name

        ' Determine whether the user login has expired by attempting
        ' to retrieve roles from the service. Call the ResetCache method
        ' to ensure that the roles are retrieved from the service. If no 
        ' roles are returned, then the login has expired. This assumes 
        ' that every valid user has been assigned to one or more roles.
        provider.ResetCache()
        Dim roles As String() = provider.GetRolesForUser(userName)
        If roles.Length = 0 Then

            MessageBox.Show( _
                "Your login has expired. Please log in again to access " & _
                "the roles service.", "Attempting to access user roles...")

            ' Call ValidateUser with empty strings in order to 
            ' display the login dialog box configured as a 
            ' credentials provider.
            If Not System.Web.Security.Membership.ValidateUser( _
                String.Empty, String.Empty) Then

                MessageBox.Show("Unable to authenticate. " & _
                    "Cannot retrieve user roles.", "Not logged in", _
                    MessageBoxButtons.OK, MessageBoxIcon.Error)
                Return

            End If

        End If

        If provider.IsUserInRole(userName, "manager") Then
            PerformManagerTask()
        End If

    Catch ex As System.Net.WebException

        MessageBox.Show( _
            "Unable to access the remote service. " & _
            "Cannot retrieve user roles.", "Warning", _
            MessageBoxButtons.OK, MessageBoxIcon.Warning)

    End Try

End Sub

注解

GetRolesForUser 方法检索当前经过身份验证的用户的角色信息,必须在 username 参数中指定该用户。 可以通过 staticThread.CurrentPrincipal 属性获取用户名,如下所示:Thread.CurrentPrincipal.Identity.Name

服务提供商缓存有关本地文件系统的角色信息,以避免不必要的服务调用。 有关详细信息,请参阅 ClientRoleProvider 类概述。

适用于

另请参阅