protected override void OnTextChanged(EventArgs e) { Form1 form = (Form1)FindForm(); if (form == null) { base.OnTextChanged(e); return; } if (!IsUndoingRedoing && RichTextBoxUtil.ContainsUnderlineText(this)) { if (IsUnderlining) { IsUnderlining = false; } else { DictionaryManager.ClearTextCorrectness(this); } } if (!IsUndoingRedoing && RichTextBoxUtil.ContainsHighlightText(this)) { if (IsHighlighting) { IsHighlighting = false; } else { StringUtil.ClearHighlightsResults(this); } } if (IsUndoingRedoing) { IsUndoingRedoing = false; } TabManager.TabTextChange(form); TextManager.RefreshUndoRedoExternal(form); base.OnTextChanged(e); }