Override toolbar button properties and click behavior

The WinForms HTML Editor's built-in toolbar looks right for a generic document editor, but your app is not generic: an invoicing tool might want a Send icon in place of Save, a compliance app might need different tooltip text, and an app backed by a versioned content store has no use for the stock file-picker at all. This page shows how to override a built-in button's icon, tooltip, and enabled state in code, and how to replace its click behavior outright so it runs your own logic instead of the editor's default.

By default, clicking the toolbar's Save icon in WinFormHtmlEditor pops a standard SaveFileDialog, the OS file picker. If your app stores documents somewhere other than a plain file (a database, a versioned content store, a custom commit workflow), you can replace the Save icon, its tooltip, and its click behavior entirely.

Layer 1: change the icon and tooltip in code

Every built-in toolbar item is exposed as a typed ToolStripButton property on WinFormHtmlEditor (BtnSave, BtnNew, BtnPrint, …), and the same live items are reachable via ToolbarItemOverrider.ToolbarItems. Set the icon and tooltip from your form's Load handler (or right after InitializeComponent()). Built-in items are intentionally not editable through the Visual Studio Properties window or designer - design-time edits do not persist, and serializing the editor's own toolbar into your form is explicitly unsupported. Code is the single reliable path.

private void RunbookForm_Load(object sender, EventArgs e) {     htmlEditor1.BtnSave.Image = MyIcons.CommitRunbook16;     htmlEditor1.BtnSave.ToolTipText = "Commit runbook (Ctrl+S)"; }

Private Sub RunbookForm_Load(sender As Object, e As EventArgs)     htmlEditor1.BtnSave.Image = MyIcons.CommitRunbook16     htmlEditor1.BtnSave.ToolTipText = "Commit runbook (Ctrl+S)" End Sub

Layer 2: runtime tweaks for state-dependent UI

Toggle a button's visibility or enabled state at runtime the same way: disable Save when nothing has changed, hide it in a read-only mode, and re-enable it on the next edit.

private void RunbookForm_Load(object sender, EventArgs e) {     htmlEditor1.BtnSave.Visible = !isReviewMode;     htmlEditor1.BtnSave.Enabled = false;     htmlEditor1.HtmlChanged += (s, a) => htmlEditor1.BtnSave.Enabled = true;     // Hide Paste-From-Word for engineers without an Office license.     htmlEditor1.BtnPasteFromMsWord.Visible = userHasOfficeLicense; }

Private Sub RunbookForm_Load(sender As Object, e As EventArgs)     htmlEditor1.BtnSave.Visible = Not isReviewMode     htmlEditor1.BtnSave.Enabled = False     htmlEditor1.HtmlChanged += Function(s, a) CSharpImpl.__Assign(htmlEditor1.BtnSave.Enabled, True)     ' Hide Paste-From-Word for engineers without an Office license.     htmlEditor1.BtnPasteFromMsWord.Visible = userHasOfficeLicense End Sub  Private Class CSharpImpl     <System.Obsolete("Please refactor calling code to use normal Visual Basic assignment")>     Shared Function __Assign(Of T)(ByRef target As T, value As T) As T         target = value         Return value     End Function

Every built-in button is reachable the same way: BtnNew, BtnOpen, BtnSave, BtnCut, BtnCopy, BtnPaste, BtnPasteFromMsWord, BtnBold, BtnItalic, BtnUnderline, BtnFormatReset, BtnFormatUndo, BtnFormatRedo, BtnPrint, BtnSpellCheck, BtnSearch, BtnHighlightColor, BtnFontColor, BtnHyperlink, BtnImage, BtnInsertYouTubeVideo, BtnTable, BtnSymbol, BtnHorizontalRule, BtnOrderedList, BtnUnOrderedList, BtnAlignLeft, BtnAlignCenter, BtnAlignRight, BtnOutdent, BtnIndent, BtnStrikeThrough, BtnSuperScript, BtnSubscript, BtnBodyStyle. Combos: CmbFontName, CmbFontSize, CmbTitleInsert.

Layer 3: replacing the click behavior

Changing the icon and tooltip only changes how the button looks - the click still opens the OS file picker. To replace that, subscribe to ToolbarItemOverrider.SaveButtonClicked. Once a handler is attached, the editor's default action does not run; your code runs instead.

private void RunbookForm_Load(object sender, EventArgs e) {     htmlEditor1.ToolbarItemOverrider.SaveButtonClicked += (s, e) =>     {         // Skip the OS file picker entirely. Run the company commit pipeline.         var commitMessage = CommitMessageDialog.ShowDialog(htmlEditor1);         if (commitMessage == null)             return;         var html = htmlEditor1.Content.GetDocumentHtml();         RunbookRepository.Commit(currentRunbookId, html, commitMessage, currentUser);         htmlEditor1.BtnSave.Enabled = false; // re-enabled on next HtmlChanged     }; }

Private Sub RunbookForm_Load(sender As Object, e As EventArgs)     htmlEditor1.ToolbarItemOverrider.SaveButtonClicked += Sub(s, e)                                                               ' Skip the OS file picker entirely. Run the company commit pipeline.                                                               Dim commitMessage = CommitMessageDialog.ShowDialog(htmlEditor1)                                                               If commitMessage Is Nothing Then Return                                                               Dim html = htmlEditor1.Content.GetDocumentHtml()                                                               RunbookRepository.Commit(currentRunbookId, html, commitMessage, currentUser)                                                               htmlEditor1.BtnSave.Enabled = False ' re-enabled on next HtmlChanged                                                           End Sub End Sub

A toolbar button's icon, tooltip, and keyboard shortcut can stay the same while its click action is fully replaced - for example, routing Save to a custom commit pipeline with an audit trail, peer-review queue, and SQL backend.

The full override menu

The same pattern applies to any toolbar button - for example, Save (commit pipeline), New (clear-with-confirmation), or Print (render-to-PDF service). Events open for override on ToolbarItemOverrider include BoldButtonClicked, ItalicButtonClicked, UnderlineButtonClicked, ImageButtonClicked, HyperLinkButtonClicked, TableInsertButtonClicked, NewButtonClicked, OpenButtonClicked, SaveButtonClicked, PrintButtonClicked, SpellCheckButtonClicked, SearchButtonClicked, SymbolInsertButtonClicked, YouTubeVideoInsertButtonClicked, plus the combo-value-changed events FontNameComboValueChanged, FontSizeComboValueChanged, and TitleInsertComboValueChanged. The complete set lives in ToolbarItemOverrideHelper.

Picking the right layer

• To change only icon, tooltip, or visibility, set the BtnXxx property at runtime (in Load or after InitializeComponent) - built-in items have no design-time Properties-grid path, by design.
• To add work alongside the editor's action (audit log, telemetry, validation), subscribe to ToolbarItemOverrider.XxxButtonClicked and call the matching Formatting/Content/Editor service afterward.
• To replace the action entirely, subscribe and skip the call to the original service.