PageInfoDataProviderBase Class

using DevExpress.XtraPrinting;
using System.Web;
// ...

class CustomPageInfoDataProvider : PageInfoDataProviderBase {
    readonly HttpContext httpContext;
    public CustomPageInfoDataProvider(HttpContext httpContext) {
        this.httpContext = httpContext;
    }

    public override string GetText(PrintingSystemBase ps, PageInfoTextBrickBase brick) {
        if (brick.PageInfo != PageInfo.UserName) {
            return null;
        }
        if (httpContext == null)
            return "<No Information>";
        var user = httpContext.User;
        if (user == null || user.Identity == null)
            return "<Please enable Forms or Windows security>";
        var identity = user.Identity;
        return identity.IsAuthenticated
            ? identity.Name
            : "<Guest>";
    }
}

Imports DevExpress.XtraPrinting
Imports System.Web
' ...

Class CustomPageInfoDataProvider
    Inherits PageInfoDataProviderBase
    ReadOnly httpContext As HttpContext
    Public Sub New(httpContext As HttpContext)
        Me.httpContext = httpContext
    End Sub

    Public Overrides Function GetText(ps As PrintingSystemBase, brick As PageInfoTextBrickBase) As String
        If brick.PageInfo <> PageInfo.UserName Then
            Return Nothing
        End If
        If httpContext Is Nothing Then
            Return "<No Information>"
        End If
        Dim user = httpContext.User
        If user Is Nothing OrElse user.Identity Is Nothing Then
            Return "<Please enable Forms or Windows security>"
        End If
        Dim identity = user.Identity
        Return If(identity.IsAuthenticated, identity.Name, "<Guest>")
    End Function
End Class

using DevExpress.XtraPrinting;
using DevExpress.XtraReports.UI;
using DevExpress.XtraReports.Web.WebDocumentViewer;
using System;
using System.Web;
// ...

class CustomWebDocumentViewerOperationLogger : WebDocumentViewerOperationLogger {
    public override Action BuildStarting(string reportId, XtraReport report, ReportBuildProperties buildProperties) {
        var httpContext = HttpContext.Current;
        return () => {
            report.PrintingSystem.AddService(typeof(PageInfoDataProviderBase), new CustomPageInfoDataProvider(httpContext));
        };
    }
}

Imports DevExpress.XtraPrinting
Imports DevExpress.XtraReports.UI
Imports DevExpress.XtraReports.Web.WebDocumentViewer
Imports System
Imports System.Web
' ...

Class CustomWebDocumentViewerOperationLogger
    Inherits WebDocumentViewerOperationLogger
    Public Overrides Function BuildStarting(reportId As String, report As XtraReport, buildProperties As ReportBuildProperties) As Action
        Dim MyHttpContext = HttpContext.Current
        Return Function() 
        report.PrintingSystem.AddService(GetType(PageInfoDataProviderBase), New CustomPageInfoDataProvider(MyHttpContext))
        End Function
    End Function
End Class

using DevExpress.XtraReports.Web.WebDocumentViewer;
// ...

protected void Application_Start(object sender, System.EventArgs e) {
    DefaultWebDocumentViewerContainer.Register<WebDocumentViewerOperationLogger, CustomWebDocumentViewerOperationLogger>();
}

Imports DevExpress.XtraReports.Web.WebDocumentViewer
' ...

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
    DefaultWebDocumentViewerContainer.RegisterSingleton(Of WebDocumentViewerOperationLogger, CustomWebDocumentViewerOperationLogger)()
End Sub