GoText value changed event

I have a GoText with GoTextEditorStyle = NumericUpDown.

When the user enter the GoText object I get an event, but I need an event, when the user click on the NumericUpDown buttons.

Could you make use of the NumericUpDown.ValueChanged event handler? If so, you can replace your regular GoText objects with a subclass that overrides DoBeginEdit:
public override void DoBeginEdit(GoView view) {
Control ctrl = this.Editor.GetControl(view);
if (ctrl != null) {
ctrl.ValueChanged += …