using DevExpress.XtraBars.Docking;

// Prevent a panel from being dragged from a container.
private void dockManager1_StartDocking(object sender, DockPanelCancelEventArgs e) {
   DockPanel parentPanel = e.Panel.ParentPanel;
      e.Cancel = parentPanel != null;
}

// Prevent a panel from being docked to another panel.
private void dockManager1_Docking(object sender, DockingEventArgs e) {
   e.Cancel = e.TargetPanel != null;
}

Imports DevExpress.XtraBars.Docking

' Prevent a panel from being dragged from a container.
Private Sub DockManager1_StartDocking(ByVal sender As Object, ByVal e As DockPanelCancelEventArgs) _
Handles DockManager1.StartDocking
   Dim parentPanel As DockPanel = e.Panel.ParentPanel
   e.Cancel = Not parentPanel Is Nothing
End Sub

' Prevent a panel from being docked to another panel.
Private Sub DockManager1_Docking(ByVal sender As Object, ByVal e As DockingEventArgs) _
Handles DockManager1.Docking
   e.Cancel = Not e.TargetPanel Is Nothing
End Sub