Opening a hyperlink in the default browser instead of MSIE

Opening a hyperlink in the default browser instead of MSIE

By default, hyperlinks inside the editor are activated by Ctrl+Click. When the user Ctrl-Clicks a link in the WYSIWYG design surface, the editor calls System.Diagnostics.Process.Start with UseShellExecute = true, which routes the request through the Windows shell. The shell launches the user's registered default browser (Chrome, Edge, Firefox, Brave, whatever the user picked in Windows Settings) -- not the embedded Internet Explorer that hosts the editor surface.

This is the built-in behaviour. You do not need to write any code to get it. The relevant snippet from the editor's internal Ctrl+Click handler looks like this:

// inside the editor, on Ctrl+Click of an <a> element:
string href = anchor.GetAttribute("href");
Process.Start(new ProcessStartInfo(href, string.Empty)
{
    UseShellExecute = true     // KEY: route through the Windows shell
});

The UseShellExecute = true flag is the load-bearing piece. Without it, Process.Start would expect href to be the full path to an executable; with it, Windows treats href as a document/URL and opens it with the registered handler.

Preview mode

When the editor is in EditorModes.ReadOnlyPreview the document is rendered by the embedded WebBrowser as a normal web page. In that mode, ordinary (un-modified) clicks navigate inside the embedded browser. To force preview-mode clicks to open in the default browser instead, host the editor's preview content in SpicePreviewWebBrowser, which intercepts navigations and shells them out via the same Process.Start + UseShellExecute pattern.

Opening links from your own code

If you want to open a URL programmatically -- for example, from a custom toolbar button or a hyperlink click handler on your own form -- use exactly the same pattern. Subscribing to HtmlElementClicked and filtering for HtmlElementTypes.Hyperlink gives you the recipe:

htmlEditor1.HtmlElementClicked += (sender, e) =>
{
    if (e.ElementType != HtmlElementTypes.Hyperlink)
        return;
    string href = e.ClickedElement.GetAttribute("href");
    if (string.IsNullOrWhiteSpace(href))
        return;
    try
    {
        Process.Start(new ProcessStartInfo { FileName = href, UseShellExecute = true }); // Cancel the editor's built-in navigation so MSIE does not also try to handle it.        e.EventData.ReturnValue = false;    }    catch (Exception ex)    {        MessageBox.Show("Cannot open link: " + ex.Message);    }};

htmlEditor1.HtmlElementClicked += Sub(sender, e)
                                      If e.ElementType IsNot HtmlElementTypes.Hyperlink Then Return
                                      Dim href As String = e.ClickedElement.GetAttribute("href")
                                      If String.IsNullOrWhiteSpace(href) Then Return
                                      Try
                                          Process.Start(New ProcessStartInfo With {
                                                                                        .FileName = href,
                                                                                        .UseShellExecute = True
                                                                                    }) ' Cancel the editor's built-in navigation so MSIE does not also try to handle it.        e.EventData.ReturnValue = false;    }    catch (Exception ex)    {        MessageBox.Show("Cannot open link: " + ex.Message);    }};
                                      Finally
                                      End Try

Caveats

• Validate the URL before calling Process.Start. UseShellExecute = true will happily try to launch file: URLs, mailto: URIs, or even local .exe paths if a malicious document contains them. If you are loading documents from untrusted sources, scheme-filter to http and https before shelling out.
• Wrap the call in try/catch. A user with no default browser configured, or a URL with a scheme no application has registered, will throw Win32Exception.
• The default behaviour only applies to Ctrl+Click in WYSIWYG mode. A plain click in WYSIWYG positions the caret in the link text so the user can edit it -- that is the design intent for an editor surface.

Ask your AI to do this

Using the SpiceLogic WinForms HTML Editor already referenced in my project, make sure hyperlink clicks always open in the user's default browser instead of the embedded MSIE surface, including when the document is shown through SpicePreviewWebBrowser in EditorModes.ReadOnlyPreview. Also add my own toolbar button that opens the link under the caret the same way, by reading the href off the clicked element from the HtmlElementClicked event, filtered to HtmlElementTypes.Hyperlink, and launching it with UseShellExecute set to true. Confirm the exact event and property names with the SpiceLogic MCP tools before writing any code.