Replacing the editor's right-click context menu

The WinForms HTML Editor's default right-click context menu covers general editing commands: cut, copy, paste, table commands, image properties. Your app may need more than that - a CRM note editor that lets a rep link the current selection to a support ticket, or a ticketing app that turns selected text into a task, right from the same right-click gesture users already reach for. Replace the default menu with your own ContextMenuStrip when your document needs commands like these instead of, or alongside, the built-in ones. This page shows how to swap the menu, enable or disable items based on the current selection, and observe right-clicks without touching the built-in menu at all.

Replace the menu via EditorContextMenuStrip

The editor exposes a single property for this: EditorContextMenuStrip, of type System.Windows.Forms.ContextMenuStrip. Assign your own strip and the editor uses it whenever the user right-clicks inside the document surface.

private void NoteEditorForm_Load(object sender, EventArgs e) {     var menu = new ContextMenuStrip();     var linkToTicket = new ToolStripMenuItem("Link to Ticket...");     linkToTicket.Click += (s, args) =>     {         var ticketId = TicketPicker.Show(this);         if (ticketId != null)         {             string anchor = $"<a href=\"crm://ticket/{ticketId}\">#{ticketId}</a>";             htmlEditor1.Content.InsertHtmlAtCaret(anchor);         }     };     var convertToTask = new ToolStripMenuItem("Convert Selection to Task");     convertToTask.Click += (s, args) =>     {         string selected = htmlEditor1.Selection.GetSelectedHtml();         if (!string.IsNullOrWhiteSpace(selected))             TaskService.CreateFromHtml(currentAccount.Id, selected);     };     menu.Items.Add(linkToTicket);     menu.Items.Add(new ToolStripSeparator());     menu.Items.Add(convertToTask); // Hand the strip to the editor. From now on, right-clicking inside the    // note shows this menu instead of the built-in one.    htmlEditor1.EditorContextMenuStrip = menu;}

Private Sub NoteEditorForm_Load(sender As Object, e As EventArgs)     Dim menu = New ContextMenuStrip()     Dim linkToTicket = New ToolStripMenuItem("Link to Ticket...")     linkToTicket.Click += Sub(s, args)                               Dim ticketId = TicketPicker.Show(Me)                               If ticketId IsNot Nothing Then                                   Dim anchor As String = $"<a href=""crm://ticket/{ticketId}"">#{ticketId}</a>"                                   htmlEditor1.Content.InsertHtmlAtCaret(anchor)                               End If                           End Sub     Dim convertToTask = New ToolStripMenuItem("Convert Selection to Task")     convertToTask.Click += Sub(s, args)                                Dim selected As String = htmlEditor1.Selection.GetSelectedHtml()                                If Not String.IsNullOrWhiteSpace(selected) Then TaskService.CreateFromHtml(currentAccount.Id, selected)                            End Sub     menu.Items.Add(linkToTicket)     menu.Items.Add(New ToolStripSeparator())     menu.Items.Add(convertToTask) ' Hand the strip to the editor. From now on, right-clicking inside the    // note shows this menu instead of the built-in one.    htmlEditor1.EditorContextMenuStrip = menu;} End Sub

[IMAGE: editor-context-menu-strip.png -- right-click menu showing Link to Ticket and Convert to Task in place of the default menu]

Disable items based on current state

To disable an item conditionally, for example greying out a command when there is no selection, handle the Opening event on the EditorContextMenuStrip (a normal Windows Forms ContextMenuStrip):

menu.Opening += (s, args) => {     string selected = htmlEditor1.Selection.GetSelectedHtml();     convertToTask.Enabled = !string.IsNullOrWhiteSpace(selected); };

menu.Opening += Sub(s, args)                     Dim selected As String = htmlEditor1.Selection.GetSelectedHtml()                     convertToTask.Enabled = Not String.IsNullOrWhiteSpace(selected)

[IMAGE: context-menu-opening-state.png -- menu with Convert to Task disabled because there is no selection]

The ContextMenuShowing event: a notification hook

To observe right-clicks without replacing the menu, for example for usage analytics, handle the ContextMenuShowing event. It fires whenever the built-in menu is about to appear, and its event args give you the cursor position relative to the editor:

htmlEditor1.ContextMenuShowing += (sender, e) => {     // e.OffsetMousePosition is the cursor location relative to the editor surface.     AnalyticsClient.Track(         "NoteEditorRightClick",         new { x = e.OffsetMousePosition.X, y = e.OffsetMousePosition.Y }); };

Note: ContextMenuShowingEventArgs only carries OffsetMousePosition. There is no Cancel property and no MenuItems collection, so you cannot suppress or modify the built-in menu from this event. To show a different menu, use EditorContextMenuStrip instead; this event is for observation only.

[IMAGE: context-menu-showing-event.png -- event firing as the built-in menu appears, with the offset coordinates highlighted]

Because the strip is built once in code, you can extend it later, for example adding another ToolStripMenuItem for a new command, without changing how it is wired to the editor.