Inserting HTML at current Caret position

Inserting HTML at the caret is a common need: the user picks a command in your application and a prepared snippet lands exactly where they were typing. The method for that is InsertHtml, on the editor's content service.

The command can sit anywhere in your own UI - an ordinary button on your form, a menu item, or a custom button you add to the editor's built-in toolbar. Toolbar buttons are added in code rather than through the Visual Studio designer: Toolbar1 and its buttons are exposed as read-only accessors and are deliberately not serialized into InitializeComponent, so that the control owns its own toolbar layout. Add a custom button to the built-in toolbar shows that in full.

The examples below assume the editor instance is named winFormHtmlEditor1 and the button is named btnInsert.

Wire that button's Click event to a handler - btnInsert_Click here - the same way you would wire any other button in your application. Your handler runs on the click, so anything it does to the editor happens against the live document:

Now, within that click event handler, you can write code like this:

private void btnInsert_Click(object sender, EventArgs e)
{
    winFormHtmlEditor1.Content.InsertHtml("<span style='color:red;'>Sep 30</span> <span style='color:blue;'>renewal</span>", keepSelected: true);
}

Private Sub btnInsert_Click(sender As Object, e As EventArgs)
    winFormHtmlEditor1.Content.InsertHtml("<span style='color:red;'>Sep 30</span> <span style='color:blue;'>renewal</span>", keepSelected:=True)
End Sub

Now, you can run the application. Say your document contains a client notice, and your caret is positioned immediately before the word 'deadline'.

Clicking the button runs that handler, and the snippet lands at the caret:

You see that the inserted snippet is highlighted. That is because we passed the second argument of the method "keepSelected = true". If you pass that argument as false, then the inserted snippet will not be highlighted upon insertion. Anyway, once you deselect that part, you will see the snippet as follows:

Ask your AI to do this

Using the SpiceLogic WinForms HTML Editor already referenced in my project, add a toolbar button labeled "Insert signature" whose click handler calls Content.InsertHtml to drop a small colored HTML snippet at the current caret position, and show me the practical difference between passing keepSelected as true versus false so I can pick the right behavior for my composer. Confirm the real InsertHtml signature through the SpiceLogic MCP tools before writing the click handler.