WPF HTML Editor Control

Every toolbar button is a XAML vector path, not a PNG asset. The icon set was rebuilt in the 3.0 line and stays crisp at 100%, 125%, 150%, 175%, and 200% DPI - and on 4K monitors and per-monitor DPI configurations. The editor doesn't look like a 2010 component dropped next to your modern WPF UI.

Some workflows need an HTML fragment. Some need a full document. The editor exposes both:

• BodyHtml - the inner HTML of the document body, useful when you store content inside your own page, template, or database column.
• DocumentHtml - the full HTML document including wrapper, header, and DOCTYPE, useful when you save or send standalone HTML.

HTML5 is the default document type in 3.0, with override controls available for older render targets.

End users can insert images from a local file, an absolute URL, or directly from the clipboard. Clipboard images can be embedded as Base64 Data URIs so the HTML is self-contained, or saved to a base folder and referenced by relative path using the editor's BaseUrl.

Pasted screenshots and photos auto-resize to a sensible maximum width by default - controlled by MaxPastedImageWidth - so the document stays portable across email clients and web hosts. When you need to publish, the EmbedLocalImagesAsBase64() method walks the document and converts every local image to a Base64 Data URI in a single call.

YouTube embedding is supported through the toolbar, with the option to add ?rel=0 to keep related-videos suggestions out of the embed. Hyperlinks support cross-document bookmark targets through the hyperlink dialog.

Set one property and the entire editor UI reflows:

editor.Language = EditorLanguage.German;

Every toolbar tooltip, dialog caption, dialog button, and context-menu item appears in the chosen language. Fourteen UI languages are bundled: English (US), English (UK), German, Dutch, French, Spanish, Italian, Danish, Polish, Norwegian, Czech, Swedish, Portuguese (Brazil), and Portuguese (Portugal).

UI language and spell-check language are independent: you can run a German UI with an English spell-check dictionary if your users edit English content in a German shell. UI language is set with Language; spell-check language is set with SpellCheckOption.SpellCheckLanguage.

An embedded editor shouldn't fight the host application for keyboard shortcuts.

The KeyBindings manager exposes binding, unbinding, overriding, disabling, enabling, and querying for editor actions represented by EditorActionId. Thirty-five actions are covered - bold, italic, underline, cut, copy, paste, undo, redo, search, spell check, ordered and unordered list commands, alignment commands, insert commands for table, image, hyperlink, symbol, and YouTube video, font color, highlight color, indent, outdent, and more.

Use it to keep familiar shortcuts where users expect them, or to let your host application's global commands win when the editor has focus.

The editor uses standard WPF theming. Swap a single ResourceDictionary to retheme it - light, dark, or your own design system colors and typography. The XAML vector toolbar adapts to brushes you supply. No proprietary skin engine to learn, no theme format to bolt on. Standard WPF resource resolution, the way you already style the rest of your application.

For teams that need to retemplate dialogs end to end or align deeply with a corporate WPF design system, the Source Code License includes the full source code of the control.

A GUI CSS style builder available at both design time (through the WPF property surface) and at runtime (from the editor toolbar). End users pick font, size, color, background, border, margin, and padding from familiar controls - no CSS knowledge required. The editor writes the equivalent inline or class-scoped CSS into the document.

To add your own pages to the style builder - for example, a "Corporate Branding" tab with your standard color palette - implement IEditorStylePage and decorate the form with FormSelectorPageAttribute.

• Content service. Read, set, insert, transform, and export HTML through the Content service. Sub-services for MailMerge (placeholder fields) and TableAuthoringService (programmatic table operations).
• Caret service. Get and set caret position by point or by index through the Caret service.
• Editor commands. Cut, copy, paste, undo, redo, search, replace, print, and command execution through the Editor service.
• Formatting service. Apply bold, italic, underline, font, colors, alignment, lists, headings, and format removal through Formatting.
• Selection service. Read selected HTML, select text, select all, trim selections through Selection.
• State query service. Ask whether the current selection is bold, italic, inside a table, undoable, or redoable - 37 query methods through StateQuery.
• HTML-Changed event. HtmlChanged fires immediately when the document changes - useful for dirty-flag tracking and live preview elsewhere in the host.
• Base64 image conversion. EmbedLocalImagesAsBase64() converts every local image in the document to a Base64 Data URI in one call.
• Email-ready output. Content.GetEmailMessageWithLocalImagesEmbedded() returns a fully populated MailMessage with images embedded, ready to send through SMTP.
• Enter-key behavior. Choose between paragraph (<p>) and line-break (<br>) on Enter, through EnterKeyResponse.
• HTML5 DOCTYPE by default. Legacy DOCTYPEs available through a property toggle for older render targets.
• License-key activation. Set WpfHtmlEditor.LicenseKey once at application startup. No license file to ship.