Enabling MenuStrip MDI Merging in Tabbed MDI Mode

By default, Dock supports MDI menu merging only in standard MDI mode. Since the .NET MenuStrip control supports ways to manually merge menus, you can also integrate MDI menu merging in tabbed MDI mode.

This code demonstrates how to support MenuStrip MDI merging in tabbed MDI mode:

/// <summary>
/// Occurs when the value of the <see cref="SelectedDocument"/> property changes.
/// </summary>
/// <param name="sender">Sender of the event.</param>
/// <param name="e">Event arguments.</param>
private void dockManager_SelectedDocumentChanged(object sender, TabbedMdiWindowEventArgs e) {
	// Since automated MDI menu merging doesn't occur for MenuStrips unless in standard MDI mode,
	//   if we are in tabbed MDI mode, we must manually merge the child MenuStrip
	if (dockManager.DocumentMdiStyle == DocumentMdiStyle.Tabbed) {
		// Revert any currently merged MenuStrip
		ToolStripManager.RevertMerge(mdiParentMenuStrip);

		// If a new document is selected...
		if (e.TabbedMdiWindow != null) {
			// Try to find a MenuStrip and merge it
			MenuStrip menuStrip = this.FindMergableMenuStrip(e.TabbedMdiWindow);
			if (menuStrip != null)
				ToolStripManager.Merge(menuStrip, mdiParentMenuStrip);
		}
	}
}

/// <summary>
/// Recursively looks for a mergable <c>MenuStrip</c>.
/// </summary>
/// <param name="parentControl">The parent <c>Control</c> to search.</param>
/// <returns>The <c>MenuStrip</c> that was found, if any.</returns>
private MenuStrip FindMergableMenuStrip(Control parentControl) {
	foreach (Control control in parentControl.Controls) {
		if (control is MenuStrip) {
			if (((MenuStrip)control).AllowMerge)
				return (MenuStrip)control;
		}				
		if (control.HasChildren) {
			MenuStrip menuStrip = this.FindMergableMenuStrip(control);
			if (menuStrip != null)
				return menuStrip;
		}
	}
	return null;
}