We use cookies to give you the best experience on our website. If you continue to browse, then you agree to our privacy policy and cookie policy. Image for the cookie policy date
Unfortunately, activation email could not send to your email. Please try again.
Syncfusion Feedback

Render time for very large lists

Thread ID:





147470 Sep 11,2019 06:42 PM UTC Sep 12,2019 11:20 AM UTC ASP.NET Core - EJ 2 1
Tags: ComboBox
Michael J Norman
Asked On September 11, 2019 06:42 PM UTC

Is there a way to minimize the control render time when a very large number of items are loaded?  For example 5000+?  Currently you see the standard html control for a second or so then the ej control renders.

Narayanasamy Panneer Selvam [Syncfusion]
Replied On September 12, 2019 11:20 AM UTC

Hi Michael, 
Good day to you.

Yes, you can increase control rendering speed while you load huge amount of data. To resolve this problem, you have to load data to the control on-demand. In the below sample we have fetched and loaded data to the control using Virtual Scrolling technique. The data will be load into combobox suggestion popup on-demand, while scrolling. We have done this in ComboBox’s open event. Kindly refer to the following code snippet.
Code example:  
    var isInitial = false; 
    function onOpen(args) { 
      if (!this.isInitial) { 
        var start = 11; 
        var end = 20; 
        var instance = document.getElementById("customers").ej2_instances[0]; 
        var listElement = instance.popupObj.element.firstChild; 
        listElement.addEventListener('scroll', () => { 
          if ((listElement.scrollTop + listElement.offsetHeight >= listElement.scrollHeight)) { 
            var filterQuery = this.query.clone(); 
            this.dataSource.executeQuery(filterQuery.range(start, end)).then((event) => { 
              start = end; 
              end += 5; 
            }).catch((e) => { 
For your convenience we have prepared a sample, please get it from the below link, 
Kindly let us know, if you need further assistance on this. 
Narayanasamy P.  


This post will be permanently deleted. Are you sure you want to continue?

Sorry, An error occured while processing your request. Please try again later.

Please sign in to access our forum

This page will automatically be redirected to the sign-in page in 10 seconds.

Warning Icon You are using an outdated version of Internet Explorer that may not display all features of this and other websites. Upgrade to Internet Explorer 8 or newer for a better experience.Close Icon

Live Chat Icon For mobile
Live Chat Icon