const numberBox = $('#numberBoxContainer').dxNumberBox('instance');

numberBox.registerKeyHandler('backspace', function(e) {
    // The argument 'e' contains information about the event
});
numberBox.registerKeyHandler('space', function(e) {
    // ...
});

import { ViewChild, AfterViewInit } from '@angular/core';
import { DxNumberBoxComponent } from 'devextreme-angular/ui/number-box';

@Component({
    imports: [DxNumberBoxComponent],
    // ...
})
export class AppComponent implements AfterViewInit {
    @ViewChild(DxNumberBoxComponent, { static: false }) numberBox!: DxNumberBoxComponent;
    // Prior to Angular 8
    // @ViewChild(DxNumberBoxComponent) numberBox: DxNumberBoxComponent;

    ngAfterViewInit () {
        this.numberBox.instance.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information about the event
        });
        this.numberBox.instance.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}

<template>
    <DxNumberBox ref="numberBoxRef" />
</template>

<script setup lang="ts">
import { onMounted, ref } from 'vue';
import { DxNumberBox } from 'devextreme-vue/number-box';

const numberBoxRef = ref<DxNumberBox | null>(null);

onMounted(() => {
    numberBoxRef.value.instance.registerKeyHandler('backspace', function(e) {
        // The argument "e" contains information about the event
    });
    numberBoxRef.value.instance.registerKeyHandler('space', function(e) {
        // ...
    });
})

</script>

import React, { useRef, useEffect } from 'react';
import { NumberBox, type NumberBoxRef } from 'devextreme-react/number-box';

function App() {
    const numberBoxRef = useRef<NumberBoxRef>(null);

    useEffect(() => {
        const numberBox = numberBoxRef.current.instance();
        numberBox.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information about the event
        });
        numberBox.registerKeyHandler('space', function(e) {
            // ...
        });
    }, []);

    return (
        <NumberBox ref={numberBoxRef} />
    );
}