public void ShowPage(
    IPage page
)

Public Sub ShowPage(
    page As IPage
)

using System;
using System.Windows.Forms;
// ...

private void Form1_Load(object sender, EventArgs e) {
    // Create a report and assign it to the Document Viewer instance.
    XtraReport1 report = new XtraReport1();
    this.documentViewer1.DocumentSource = report;

    // Create a paginated report document.
    report.CreateDocument(false);

    // Show the document's fourth page in the Document Viewer.
    this.documentViewer1.ShowPage(report.PrintingSystem.Pages[3]);
}

Imports System
Imports System.Windows.Forms
' ... 

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
    ' Create a report and assign it to the Document Viewer instance. 
    Dim report As New XtraReport1()
    Me.documentViewer1.DocumentSource = report

    ' Create a paginated report document. 
    report.CreateDocument(False)

    ' Show the document's fourth page in the Document Viewer. 
    Me.documentViewer1.ShowPage(report.PrintingSystem.Pages(3))
End Sub