JavaScript/jQuery DropDownBox - Keyboard Support

An end user can use the following keys to interact with the UI component.

Key Action
Alt + ↓ Opens the drop-down field.

You can implement a custom handler for a key using the registerKeyHandler(key, handler) method.

jQuery
JavaScript
function registerKeyHandlers () {
    const dropDownBox = $("#dropDownBoxContainer").dxDropDownBox("instance");
    dropDownBox.registerKeyHandler("backspace", function(e) {
        // The argument "e" contains information on the event
    });
    dropDownBox.registerKeyHandler("space", function(e) {
        // ...
    });
}
Angular
TypeScript
import { ..., ViewChild, AfterViewInit } from '@angular/core';
import { DxDropDownBoxModule, DxDropDownBoxComponent } from 'devextreme-angular';
// ...
export class AppComponent implements AfterViewInit {
    @ViewChild(DxDropDownBoxComponent, { static: false }) dropDownBox: DxDropDownBoxComponent;
    // Prior to Angular 8
    // @ViewChild(DxDropDownBoxComponent) dropDownBox: DxDropDownBoxComponent;

    ngAfterViewInit () {
        this.dropDownBox.instance.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.dropDownBox.instance.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxDropDownBoxModule
    ],
    // ...
})
Vue
<template>
    <DxDropDownBox :ref="myDropDownBoxRef" />
</template>
<script>
import 'devextreme/dist/css/dx.light.css';

import DxDropDownBox from 'devextreme-vue/drop-down-box';

const myDropDownBoxRef = 'my-drop-down-box';

export default {
    components: {
        DxDropDownBox
    },
    data() {
        return {
            myDropDownBoxRef
        }
    },
    computed: {
        dropDownBox: function() {
            return this.$refs[myDropDownBoxRef].instance;
        }
    },
    mounted: function() {
        this.dropDownBox.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.dropDownBox.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
</script>
React
App.js
import React from 'react';
import 'devextreme/dist/css/dx.light.css';

import { DropDownBox } from 'devextreme-react/drop-down-box';

class App extends React.Component {
    constructor(props) {
        super(props);

        this.dropDownBoxRef = React.createRef();
    }

    render() {
        return (
            <DropDownBox ref={this.dropDownBoxRef} />
        );
    }

    get dropDownBox() {
        return this.dropDownBoxRef.current.instance;
    }

    componentDidMount() {
        this.dropDownBox.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.dropDownBox.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}

export default App;
See Also