This event occurs when the component detects a spelling error in a control. This happens while a spell dialog is displayed (see the CheckControl(ISpellCheckableEditor) method) or while the component is painting the red wavy underlines that mark misspelled words in dynamic mode (see the SetSpellChecking(Control, bool) method).

The event parameters have a Dialog property that allow the handler to determine whether a spell dialog is being displayed or not.

The event parameters also have a Cancel property that can be used to ignore the error.

Note that this event occurs every time a misspelled word is about to be underlined, which occurs whenever the control is painted (not just when the bad word is initially typed into the control. Because of this, one single misspelled word can cause this event to fire multiple times.