Read-Only Mode and Preview Mode: Programmatic Control

The WinForms HTML Editor exposes three operating modes through a single property on the control. Most "how do I make the editor read-only?" tickets boil down to picking the right mode and, where needed, hooking the click event so anchors still navigate.

The three editor modes

The mode is held in the EditorMode property of type SpiceLogic.HtmlEditor.Abstractions.EditorModes. The enum has three values:

Switching mode from C#

Set the property at any time after the editor has loaded. The control fires EditorModeChanged after the swap is complete so you can update surrounding UI (status bar, custom ribbon, menu radio buttons) in one place.

using SpiceLogic.HtmlEditor.Abstractions;

// Switch to Preview (read-only render) on a button click:
private void btnPreview_Click(object sender, EventArgs e)
{
    htmlEditor1.EditorMode = EditorModes.ReadOnlyPreview;
}

// Be notified after the mode actually changes:
htmlEditor1.EditorModeChanged += (s, e) =>
{
    statusLabel.Text = $"Mode: {htmlEditor1.EditorMode}";
    toolbar1.Visible = htmlEditor1.EditorMode == EditorModes.WysiwygDesign;
};

The event also fires when the user clicks the built-in Source / Preview toolbar buttons, so the same handler covers both code-driven and user-driven changes.

Read-only without leaving Design view

If you want the editing surface to stay rendered exactly as it is - for example after Save - but to stop accepting input, do not switch modes. Set htmlEditor1.Enabled = false. That disables the surface, the toolbar and the keyboard in one step, and re-enabling restores the caret where the user left it.

htmlEditor1.Enabled = false;   // lock
htmlEditor1.Enabled = true;    // unlock

Allowing link clicks in Preview

In ReadOnlyPreview the editor renders anchors as live links. By default, a click opens the href in the system default browser (see "Opening a hyperlink in the default browser instead of MSIE" for the background on why this changed). To intercept the click and run your own logic - in-app navigation, analytics, a confirmation prompt - subscribe to HtmlElementClicked and check the element type:

using SpiceLogic.HtmlEditor.Abstractions;
using SpiceLogic.HtmlEditor.WinForms.Models.BOs.EditorEventArgs;

htmlEditor1.HtmlElementClicked += (s, e) =>
{
    if (htmlEditor1.EditorMode != EditorModes.ReadOnlyPreview) return;
    if (e.ElementType != HtmlElementTypes.Hyperlink) return;

    string href = e.ClickedElement.GetAttribute("href");
    MyAppRouter.Navigate(href);   // your own handler
};

Your handler runs before the editor's built-in shell call. If you handle the URL yourself, the OS handoff effectively becomes a no-op because nothing in your code requested it.

Hiding the toolbar in read-only mode

The two factory toolbars are exposed as Toolbar1 and Toolbar2 (both ToolStrip instances). Toggle their Visible property from EditorModeChanged so the chrome follows the mode:

htmlEditor1.EditorModeChanged += (s, e) =>
{
    bool editing = htmlEditor1.EditorMode == EditorModes.WysiwygDesign;
    htmlEditor1.Toolbar1.Visible      = editing;
    htmlEditor1.Toolbar2.Visible      = editing;
    htmlEditor1.ToolbarFooter.Visible = editing;
};

Remembering the user's last mode across sessions

Persist the enum value as its name (a string), not its integer - the int values are an implementation detail and could shift if new modes are ever added. Restore on load after the editor has finished initialising:

// On form closing:
Properties.Settings.Default.LastEditorMode = htmlEditor1.EditorMode.ToString();
Properties.Settings.Default.Save();

// On form load:
if (Enum.TryParse<EditorModes>(Properties.Settings.Default.LastEditorMode, out var saved))
    htmlEditor1.EditorMode = saved;

Full example - preview-with-link-handling and Escape to go back

using System;
using System.Windows.Forms;
using SpiceLogic.HtmlEditor.Abstractions;
using SpiceLogic.HtmlEditor.WinForms;
using SpiceLogic.HtmlEditor.WinForms.Models.BOs.EditorEventArgs;

public partial class MainForm : Form
{
    public MainForm()
    {
        InitializeComponent();

        htmlEditor1.EditorModeChanged += OnEditorModeChanged;
        htmlEditor1.HtmlElementClicked += OnHtmlElementClicked;
        htmlEditor1.KeyDown += OnEditorKeyDown;
    }

    private void btnPreview_Click(object sender, EventArgs e)
    {
        htmlEditor1.EditorMode = EditorModes.ReadOnlyPreview;
    }

    private void OnEditorModeChanged(object sender, EventArgs e)
    {
        bool editing = htmlEditor1.EditorMode == EditorModes.WysiwygDesign;
        htmlEditor1.Toolbar1.Visible = editing;
        htmlEditor1.Toolbar2.Visible = editing;
        statusLabel.Text = $"Mode: {htmlEditor1.EditorMode}";
    }

    private void OnHtmlElementClicked(object sender, HtmlElementClickedEventArgs e)
    {
        if (htmlEditor1.EditorMode != EditorModes.ReadOnlyPreview) return;
        if (e.ElementType != HtmlElementTypes.Hyperlink) return;
        string href = e.ClickedElement.GetAttribute("href");
        // Custom routing instead of letting the OS open the link:
        MyAppRouter.Navigate(href);
    }

    private void OnEditorKeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Escape
            && htmlEditor1.EditorMode == EditorModes.ReadOnlyPreview)
        {
            htmlEditor1.EditorMode = EditorModes.WysiwygDesign;
            e.Handled = true;
        }
    }
}

The same code path covers all three recurring tickets: the editor flips to a true read-only render, the toolbar disappears, links are still clickable (routed through your app), and Escape returns the user to Design without losing the document.