Local Virtual Scrolling
If the DataGrid component is bound to a large dataset, you can enable the virtual scroll feature to optimize data load times and improve user navigation. The component calculates the overall number of visible rows and displays a scrollbar that allows users to navigate to any section of rows. When users release the scroll thumb, the control loads records to be displayed in the viewport and removes other rows from memory.
To allow users to scroll the DataGrid virtually, set the scrolling.mode to "virtual".
In this demo, the DataGrid is bound to a local dataset of 100,000 records. You can drag the scrollbar on the right to see that records within the viewport are updated immediately.
Feel free to share demo-related thoughts here.
If you have technical questions, please create a support ticket in the DevExpress Support Center.
Thank you for the feedback!
If you have technical questions, please create a support ticket in the DevExpress Support Center.
Backend API
<dx-data-grid
id="gridContainer"
[dataSource]="dataSource"
keyExpr="id"
[customizeColumns]="customizeColumns"
[showBorders]="true"
(onContentReady)="onContentReady($event)"
>
<dxo-load-panel [enabled]="true"></dxo-load-panel>
<dxo-scrolling mode="virtual"></dxo-scrolling>
<dxo-sorting mode="none"></dxo-sorting>
</dx-data-grid>
import { NgModule, Component, enableProdMode } from '@angular/core';
import { BrowserModule, BrowserTransferStateModule } from '@angular/platform-browser';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { DxDataGridModule } from 'devextreme-angular';
import { Service, Employee } from './app.service';
if (!/localhost/.test(document.location.host)) {
enableProdMode();
}
@Component({
selector: 'demo-app',
templateUrl: 'app/app.component.html',
styleUrls: ['app/app.component.css'],
providers: [Service],
})
export class AppComponent {
dataSource: any;
constructor(service: Service) {
this.dataSource = {
store: service.generateData(100000),
};
}
customizeColumns(columns) {
columns[0].width = 70;
}
onContentReady(e) {
e.component.option('loadPanel.enabled', false);
}
}
@NgModule({
imports: [
BrowserModule,
BrowserTransferStateModule,
DxDataGridModule,
],
declarations: [AppComponent],
bootstrap: [AppComponent],
})
export class AppModule { }
platformBrowserDynamic().bootstrapModule(AppModule);
::ng-deep #gridContainer {
height: 440px;
}
import { Injectable } from '@angular/core';
export class Employee {
id: number;
firstName: string;
lastName: string;
gender: string;
birthDate: Date;
}
const employees: Employee[] = [];
const surnames: string[] = [
'Smith',
'Johnson',
'Brown',
'Taylor',
'Anderson',
'Harris',
'Clark',
'Allen',
'Scott',
'Carter'];
const names: string[] = [
'James',
'John',
'Robert',
'Christopher',
'George',
'Mary',
'Nancy',
'Sandra',
'Michelle',
'Betty'];
const gender: string[] = ['Male', 'Female'];
let s = 123456789;
@Injectable()
export class Service {
random() {
s = (1103515245 * s + 12345) % 2147483647;
return s % (10 - 1);
}
generateData(count: number) {
let i: number;
const startBirthDate = Date.parse('1/1/1975');
const endBirthDate = Date.parse('1/1/1992');
for (i = 0; i < count; i++) {
const birthDate = new Date(startBirthDate + Math.floor(
this.random()
* (endBirthDate - startBirthDate) / 10,
));
birthDate.setHours(12);
const nameIndex = this.random();
const item = {
id: i + 1,
firstName: names[nameIndex],
lastName: surnames[this.random()],
gender: gender[Math.floor(nameIndex / 5)],
birthDate,
};
employees.push(item);
}
return employees;
}
}
// In real applications, you should not transpile code in the browser.
// You can see how to create your own application with Angular and DevExtreme here:
// https://js.devexpress.com/Documentation/Guide/Angular_Components/Getting_Started/Create_a_DevExtreme_Application/
window.exports = window.exports || {};
window.config = {
transpiler: 'ts',
typescriptOptions: {
module: 'system',
emitDecoratorMetadata: true,
experimentalDecorators: true,
},
meta: {
'typescript': {
'exports': 'ts',
},
'devextreme/localization.js': {
'esModule': true,
},
},
paths: {
'npm:': 'https://unpkg.com/',
},
map: {
'ts': 'npm:plugin-typescript@4.2.4/lib/plugin.js',
'typescript': 'npm:typescript@4.2.4/lib/typescript.js',
'@angular/core': 'npm:@angular/core@12.2.17',
'@angular/platform-browser': 'npm:@angular/platform-browser@12.2.17',
'@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic@12.2.17',
'@angular/forms': 'npm:@angular/forms@12.2.17',
'@angular/common': 'npm:@angular/common@12.2.17',
'@angular/compiler': 'npm:@angular/compiler@12.2.17',
'tslib': 'npm:tslib@2.3.1/tslib.js',
'rxjs': 'npm:rxjs@7.5.3/dist/bundles/rxjs.umd.js',
'rxjs/operators': 'npm:rxjs@7.5.3/dist/cjs/operators/index.js',
'rrule': 'npm:rrule@2.6.4/dist/es5/rrule.js',
'luxon': 'npm:luxon@1.28.1/build/global/luxon.min.js',
'es6-object-assign': 'npm:es6-object-assign@1.1.0',
'devextreme': 'npm:devextreme@23.1.6/cjs',
'devextreme/bundles/dx.all': 'npm:devextreme@23.1.6/bundles/dx.all.js',
'jszip': 'npm:jszip@3.7.1/dist/jszip.min.js',
'devextreme-quill': 'npm:devextreme-quill@1.6.2/dist/dx-quill.min.js',
'devexpress-diagram': 'npm:devexpress-diagram@2.2.2',
'devexpress-gantt': 'npm:devexpress-gantt@4.1.49',
'devextreme-angular': 'npm:devextreme-angular@23.1.6',
'@devextreme/runtime': 'npm:@devextreme/runtime@3.0.12',
'inferno': 'npm:inferno@7.4.11/dist/inferno.min.js',
'inferno-compat': 'npm:inferno-compat/dist/inferno-compat.min.js',
'inferno-create-element': 'npm:inferno-create-element@7.4.11/dist/inferno-create-element.min.js',
'inferno-dom': 'npm:inferno-dom/dist/inferno-dom.min.js',
'inferno-hydrate': 'npm:inferno-hydrate@7.4.11/dist/inferno-hydrate.min.js',
'inferno-clone-vnode': 'npm:inferno-clone-vnode/dist/inferno-clone-vnode.min.js',
'inferno-create-class': 'npm:inferno-create-class/dist/inferno-create-class.min.js',
'inferno-extras': 'npm:inferno-extras/dist/inferno-extras.min.js',
// Prettier
'prettier/standalone': 'npm:prettier@2.8.4/standalone.js',
'prettier/parser-html': 'npm:prettier@2.8.4/parser-html.js',
},
packages: {
'app': {
main: './app.component.ts',
defaultExtension: 'ts',
},
'devextreme': {
defaultExtension: 'js',
},
'devextreme/events/utils': {
main: 'index',
},
'devextreme/events': {
main: 'index',
},
'es6-object-assign': {
main: './index.js',
defaultExtension: 'js',
},
'rxjs': {
defaultExtension: 'js',
},
'rxjs/operators': {
defaultExtension: 'js',
},
},
packageConfigPaths: [
'npm:@devextreme/*/package.json',
'npm:@devextreme/runtime@3.0.12/inferno/package.json',
'npm:@angular/*/package.json',
'npm:@angular/common@12.2.17/*/package.json',
'npm:rxjs@7.5.3/package.json',
'npm:rxjs@7.5.3/operators/package.json',
'npm:devextreme-angular@23.1.6/*/package.json',
'npm:devextreme-angular@23.1.6/ui/*/package.json',
'npm:devextreme-angular@23.1.6/package.json',
'npm:devexpress-diagram@2.2.2/package.json',
'npm:devexpress-gantt@4.1.49/package.json',
],
};
System.config(window.config);
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>DevExtreme Demo</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/23.1.5/css/dx.light.css" />
<script src="https://unpkg.com/core-js@2.6.12/client/shim.min.js"></script>
<script src="https://unpkg.com/zone.js@0.12.0/dist/zone.js"></script>
<script src="https://unpkg.com/reflect-metadata@0.1.13/Reflect.js"></script>
<script src="https://unpkg.com/systemjs@0.21.3/dist/system.js"></script>
<script src="config.js"></script>
<script>
System.import("app").catch(console.error.bind(console));
</script>
</head>
<body class="dx-viewport">
<div class="demo-container">
<demo-app>Loading...</demo-app>
</div>
</body>
</html>