DevExtreme jQuery/JS - Customize the Appearance

You can customize the text field and the drop-down button using the fieldTemplate and dropDownButtonTemplate. To adjust the drop-down field, use the dropDownOptions object that contains options described in the Popup Configuration section.

jQuery
JavaScript
CSS
$(function () {
    var fruits = [
        { id: 1, text: "Apples", image: "images/Apples.svg" }, 
        { id: 2, text: "Oranges", image: "images/Oranges.svg" }, 
        { id: 3, text: "Lemons", image: "images/Lemons.svg" }, 
        { id: 4, text: "Pears", image: "images/Pears.svg" }, 
        { id: 5, text: "Pineapples", image: "images/Pineapples.svg" }
    ];
    $("#dropDownBoxContainer").dxDropDownBox({
        value: fruits[0],
        dataSource: new DevExpress.data.DataSource({
            store: new DevExpress.data.ArrayStore({ data: fruits, key: "id" }),
        }),
        dropDownOptions: {
            title: "Fruits",
            showTitle: true,
            fullScreen: true,
            showCloseButton: true
        },
        dropDownButtonTemplate: function() {
            return $("<img />").attr("src", "images/icons/custom-dropbutton-icon.svg");
        },
        fieldTemplate: function (value, fieldElement) {
            return $("<div class='custom-item' />").append(
                $("<img />").attr("src", value.image),
                $("<div class='product-name' />").dxTextBox({ value: value.text, readOnly: true })
            );
        },
        contentTemplate: function(e) {
            var list = $("<div>").dxList({
                dataSource: e.component.option("dataSource"),
                selectionMode: "single",
                onSelectionChanged: function(arg) {
                    e.component.option("value", arg.addedItems[0]);
                    e.component.close();
                } 
            });
            return list;
        }
    });
});
.custom-item {
    position: relative;
    min-height: 30px;
}
.custom-item > img {
    left: 1px;
    margin-top: 3px;
    max-height: 30px;
    width: auto;
    position: absolute;
}
.product-name  {
    display: inline-block;
    padding-left: 45px;
    text-indent: 0;
    line-height: 30px;
    font-size: 15px;
    width: 100%;
}
Angular
HTML
TypeScript
CSS
<dx-drop-down-box
    [(value)]="selectedFruit"
    [(opened)]="isDropDownBoxOpened"
    fieldTemplate="fieldTemplate"
    dropDownButtonTemplate="dropDownButtonTemplate"
    [dataSource]="dataSource">
    <dxo-drop-down-options
        title="Fruits"
        [showTitle]="true"
        [fullScreen]="true"
        [showCloseButton]="true">
    </dxo-drop-down-options>
    <dx-list 
        [dataSource]="fruits"
        selectionMode="single"
        (onSelectionChanged)="changeDropDownBoxValue($event)">
    </dx-list>
    <div *dxTemplate="let data of 'dropDownButtonTemplate'">
        <img src="images/icons/custom-dropbutton-icon.svg">
    </div>
    <div *dxTemplate="let data of 'fieldTemplate'">
        <div class="custom-item">
            <img src="{{data.image}}">
            <div class="product-name">
                <dx-text-box
                    [value]="data.text"
                    [readOnly]="true">
                </dx-text-box>
            </div>
        </div>
    </div>
</dx-drop-down-box>
import { DxDropDownBoxModule, DxListModule, DxTextBoxModule } from "devextreme-angular";
import DataSource from "devextreme/data/data_source";
import ArrayStore from "devextreme/data/array_store";
// ...
export class AppComponent {
    fruits = [
        { id: 1, text: "Apples", image: "images/Apples.svg" }, 
        { id: 2, text: "Oranges", image: "images/Oranges.svg" }, 
        { id: 3, text: "Lemons", image: "images/Lemons.svg" }, 
        { id: 4, text: "Pears", image: "images/Pears.svg" }, 
        { id: 5, text: "Pineapples", image: "images/Pineapples.svg" }
    ];
    dataSource: DataSource;
    selectedFruit = this.fruits[0];
    isDropDownBoxOpened: Boolean = false;
    constructor() {
        this.dataSource = new DataSource({
            store: new ArrayStore({ data: this.fruits, key: "id" })
        });
    }
    changeDropDownBoxValue = function (args) {
        this.selectedFruit = args.addedItems[0];
        this.isDropDownBoxOpened = false;
    }
}
@NgModule({
    imports: [
        // ...
        DxDropDownBoxModule,
        DxListModule,
        DxTextBoxModule
    ],
    // ...
})
::ng-deep .custom-item {
    position: relative;
    min-height: 30px;
}
::ng-deep .custom-item > img {
    left: 1px;
    margin-top: 3px;
    max-height: 30px;
    width: auto;
    position: absolute;
}
::ng-deep .product-name  {
    display: inline-block;
    padding-left: 45px;
    text-indent: 0;
    line-height: 30px;
    font-size: 15px;
    width: 100%;
}
ASP.NET MVC Controls
Razor C#
CSS
@(Html.DevExtreme().DropDownBox()
    .ID("dropDownBox")
    .DataSource(ds => ds.Array()
        .Key("ID")
        .Data(new JS("fruits"))
    )
    .Value(new JS("value"))
    .ContentTemplate(new TemplateName("list"))
    .DropDownButtonTemplate("<img src= 'images/icons/custom-dropbutton-icon.svg' />")
    .FieldTemplate(new TemplateName("field_template"))
    .DropDownOptions(o => o
        .Title("Fruits")
        .ShowTitle(true)
        .FullScreen(true)
        .ShowCloseButton(true)
    )
)
@using (Html.DevExtreme().NamedTemplate("list")) {
    @(Html.DevExtreme().List()
        .ID("list")
        .DataSource(new JS("component.option('dataSource')"))
        .SelectionMode(ListSelectionMode.Single)
        .OnSelectionChanged("innerList_selectionChanged")
    )
}
@using (Html.DevExtreme().NamedTemplate("field_template")) {
    <div class="custom-item">
        <img src="<% value.image %>">
        <div class="product-name">
            @(Html.DevExtreme().TextBox()
                .Value(new JS("value.text"))
                .ReadOnly(true)
            )
        </div>
    </div>
}

<script>
    var fruits = [
        { ID: 1, text: "Apples", image: "images/Apples.svg" },
        { ID: 2, text: "Oranges", image: "images/Oranges.svg" },
        { ID: 3, text: "Lemons", image: "images/Lemons.svg" },
        { ID: 4, text: "Pears", image: "images/Pears.svg" },
        { ID: 5, text: "Pineapples", image: "images/Pineapples.svg" }
    ];
    var value = fruits[0];
    function innerList_selectionChanged (e) {
        var dropDownBox = $("#dropDownBox").dxDropDownBox("instance");
        dropDownBox.option("value", e.addedItems[0]);
        dropDownBox.close();
    }
</script>
.custom-item {
    position: relative;
    min-height: 30px;
}
.custom-item > img {
    left: 1px;
    margin-top: 3px;
    max-height: 30px;
    width: auto;
    position: absolute;
}
.product-name  {
    display: inline-block;
    padding-left: 45px;
    text-indent: 0;
    line-height: 30px;
    font-size: 15px;
    width: 100%;
}
Vue
App.vue
CSS
<template>
    <div>
        <DxDropDownBox
            :value.sync="selectedFruit"
            :opened.sync="isDropDownBoxOpened"
            :data-source="dataSource"
            drop-down-button-template="dropDownButtonTemplate"
            field-template="fieldTemplate">
            <div slot="dropDownButtonTemplate" slot-scope="{ data }">
                <img src="images/icons/custom-dropbutton-icon.svg">
            </div>
            <div slot="fieldTemplate" slot-scope="{ data }">
                <div class="custom-item">
                    <img :src="data.image">
                    <div class="product-name">
                        <DxTextBox
                            :value="data.text"
                            :readOnly="true">
                        </DxTextBox>
                    </div>
                </div>
            </div>
            <DxDropDownOptions
                title="Fruits"
                :show-title="true"
                :full-screen="true"
                :show-close-button="true">
            </DxDropDownOptions>
            <DxList
                :data-source="dataSource"
                selection-mode="single"
                @selection-changed="changeDropDownBoxValue($event)">
            </DxList>
        </DxDropDownBox>
    </div>
</template>

<script>
import { DxDropDownBox, DxDropDownOptions } from "devextreme-vue/drop-down-box";
import DxList from "devextreme-vue/list";
import DxTextBox from "devextreme-vue/text-box";
import ArrayStore from "devextreme/data/array_store";

export default {
    components: {
        DxDropDownBox,
        DxList,
        DxTextBox,
        DxDropDownOptions
    },
    data() {
        const fruits = [
            { ID: 1, text: "Apples", image: "images/Apples.svg" }, 
            { ID: 2, text: "Oranges", image: "images/Oranges.svg" }, 
            { ID: 3, text: "Lemons", image: "images/Lemons.svg" }, 
            { ID: 4, text: "Pears", image: "images/Pears.svg" }, 
            { ID: 5, text: "Pineapples", image: "images/Pineapples.svg" }
        ];
        return {
            dataSource: new ArrayStore({
                data: fruits,
                key: "ID"
            }),
            isDropDownBoxOpened: false,
            selectedFruit: fruits[0]
        }
    },
    methods: {
        changeDropDownBoxValue(e) {
            this.selectedFruit = e.addedItems[0];
            this.isDropDownBoxOpened = false;
        }
    }
}
</script>
.custom-item {
    position: relative;
    min-height: 30px;
}
.custom-item > img {
    left: 1px;
    margin-top: 3px;
    max-height: 30px;
    width: auto;
    position: absolute;
}
.product-name  {
    display: inline-block;
    padding-left: 45px;
    text-indent: 0;
    line-height: 30px;
    font-size: 15px;
    width: 100%;
}