using DevExpress.XtraEditors;
using DevExpress.XtraBars.Docking2010;
using DevExpress.XtraBars.Docking2010.Views.Tabbed;
using System.Windows.Forms;

namespace DXApplication {
    public partial class Form1 : XtraForm {
        DocumentManager docManager;
        public Form1() {
            InitializeComponent();

            InitDocumentManager();
            AddChildForms(5);
            AddDocumentGroup(Orientation.Vertical, 2);
        }
        void InitDocumentManager() {
            docManager = new DocumentManager(components) {
                MdiParent = this,
                View = new TabbedView()
            };
        }
        void AddChildForms(int count) {
            for (int i = 0; i < count; i++)
                AddChildForm(i);
        }
        void AddDocumentGroup(Orientation groupOrientation, int documentIndex) {
            (docManager.View as TabbedView).Controller.CreateNewDocumentGroup(docManager.View.Documents[documentIndex] as Document, groupOrientation);
        }
        void AddChildForm(int number) {
            XtraForm childForm = new XtraForm() {
                Text = string.Format("Child Form ({0})", number),
                MdiParent = this
            };
            SimpleButton btn = new SimpleButton() {
                Text = string.Format("Button"),
                Parent = childForm
            };
            childForm.Show();
        }
    }
}

Imports DevExpress.XtraEditors
Imports DevExpress.XtraBars.Docking2010
Imports DevExpress.XtraBars.Docking2010.Views.Tabbed
Imports System.Windows.Forms

Namespace DXApplication
    Partial Public Class Form1
        Inherits XtraForm

        Private docManager As DocumentManager
        Public Sub New()
            InitializeComponent()

            InitDocumentManager()
            AddChildForms(5)
            AddDocumentGroup(Orientation.Vertical, 2)
        End Sub
        Private Sub InitDocumentManager()
            docManager = New DocumentManager(components) With {
                .MdiParent = Me,
                .View = New TabbedView()
            }
        End Sub
        Private Sub AddChildForms(ByVal count As Integer)
            For i As Integer = 0 To count - 1
                AddChildForm(i)
            Next i
        End Sub
        Private Sub AddDocumentGroup(ByVal groupOrientation As Orientation, ByVal documentIndex As Integer)
            TryCast(docManager.View, TabbedView).Controller.CreateNewDocumentGroup(TryCast(docManager.View.Documents(documentIndex), Document), groupOrientation)
        End Sub
        Private Sub AddChildForm(ByVal number As Integer)
            Dim childForm As New XtraForm() With {
                .Text = String.Format("Child Form ({0})", number),
                .MdiParent = Me
            }
            Dim btn As New SimpleButton() With {
                .Text = String.Format("Button"),
                .Parent = childForm
            }
            childForm.Show()
        End Sub
    End Class
End Namespace