Unable to customize giu.Event

[Seikaijyu]

Just now, I tried to customize an event. In the process, I found that an event would be triggered more than ten or even hundreds of times. Why? I did not encounter this problem in the predefined event
I want to know what I wrote wrong?

[Seikaijyu]

The code is as follows

package main

import (
	"fmt"
	g "github.com/AllenDang/giu"
)

var b = 0
var _ g.Widget = &EventAttribute{}

var refTable = map[string]g.Widget{}

type EventAttribute struct {
	id    string
	event *g.EventHandler
}

func (p *EventAttribute) Build() {
	p.event.Build()
}
func (p *EventAttribute) OnKeyDown(key g.Key, fn func()) *EventAttribute {
	p.event.OnKeyDown(key, fn)
	return p
}
func CreateEvent() *EventAttribute {
	var id = g.GenAutoID("EventAttribute")
	if widget, ok := refTable[id]; ok {
		return widget.(*EventAttribute)
	} else {
		refTable[id] = &EventAttribute{
			event: g.Event(),
		}
		return refTable[id].(*EventAttribute)
	}
}
func loop() {
	g.SingleWindow().Layout(
		g.Child().Size(-1, -1),
		CreateEvent().OnKeyDown(g.KeyS, func() {
			b++
			fmt.Println(b)
		}),
	)
}
func main() {
	g.SetDefaultFontSize(18)
	wnd := g.NewMasterWindow("TestWindow", 800, 480, 0)
	wnd.Run(loop)
}