I am working through Telerik's UI for ASP.NET Core tutorial on YouTube ... RPSTrackerASPCore ... and I am at the point where the instructor is walking us through adding an Upload component to the project. I am using a much more recent version of Kendo UI so I have to tweak some things to get them to work properly. So far that hasn't been a problem. But the Upload component has me stumped.

The VS projects are .Net 9.0.

I am using Telerik.UI.for.AspNet.Core (2026.1.325) and I am loading the JavaScript assets as ECMAScript modules. So here is the list of modules I am currently loading:

<script src="~/lib/kendo-ui/mjs/kendo.core.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.button.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.textbox.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.textarea.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.slider.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.tabstrip.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.dataviz.chart.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.grid.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.tilelayout.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.upload.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.draganddrop.js" type="module"></script>
<script src="~/lib/kendo-ui/mjs/kendo.aspnetmvc.js" type="module"></script>

And here is my component definition:

            @(Html.Kendo().Upload()
                .Name("files")
                .Multiple(true)
                .Async(a => a
                    .Save("SaveAttachmentsAsync", "Upload")
                    .AutoUpload(true)
                )
                .Validation(v => v.AllowedExtensions(new string[] { ".jpg", ".png", ".jpeg" }).MaxFileSize(10485760))
            )

And here is the inline JavaScript generated by the component:

<script type="module">kendo.syncReady(function(){jQuery("#files").kendoUpload({"async":{"autoUpload":true,"saveUrl":null},"multiple":true,"validation":{"allowedExtensions":[".jpg",".png",".jpeg"],"maxFileSize":10485760}});});</script>

I include this because I think it is odd that the async.saveUrl parameter is set to null.

I can use the "Select Files" button to select a file, and they do get added to the file list, but the autoupload functionality is not triggered. And there are no errors in the console. And the drag-and-drop functionality is not active. If I drag an acceptable file over the component the file (an image) just gets opened in a new browser tab.

I have breakpoints in my UploadController.SaveAttachmentsAsync method but they are never hit.

If I submit the form and break on the method that handles the page's form post request I DO see the file included in the request, so at least that part does actually work.

But none of the additional Kendo functionality seems to work. I thought perhaps I am missing an ECMAScript module that needs to be loaded but the documentation doesn't mention any. There are no errors in the browser console so there doesn't seem to be a JavaScript problem happening.

I did replace the modules with the standard vanilla kendo.all.min.js and kendo.aspnetmvc.min.js scripts but I get the exact same behavior.

So what am I missing?

Will the Telerik Agentic UI Generator be provided for ASP.NET Core?

Thanks

Hi All,

I am finding telerik videos and guides (documentation)  to be NOT very useful for learning how to use telerik. I have tried watching the videos and finding them to be outdated but still lacking guidance on how to do a thing telerik. Are the guides and video vague because this is a paid product and the goal is to not give a user true guidance on how to use the product? Or is it assumed that if you purchased telerik you should know how to use it regardless if you have had any exposure to it or not?

I feel like I have missed some prerequisite or I skip some step where you can learn how to apply these controls to you razor pages? I have even looked at and downloaded the the RPS example and attempted to follow the video and it shows you knowing on how to wire up any of the controls.

I can share what I am looking for it it helps.I have a basic index page that was built when I create my controller with views. I just want to apply telerik / kendo ui to that index page.So razor builds a view with a basic list index. I would like an example that shows me how to convert that index to use a telerik control. Do example such as that exist??

Attached are images of a test mvc .net core  that I built using the telerik project template. So if I wanted to change my index page that used data from my database to a gride view using telerik / kendo Ui is there an example any where that can show me how to do such a task>?

Thanks!!!

Thank you!

Can some one point me to a set of good instructions that a beginner with telerik can follow?

Currently I am feeling we made a mistake purchasing a license for this product as we can't make use of it..

Tried Looking here

https://www.telerik.com/aspnet-core-ui/documentation/html-helpers/data-management/grid

First i downloaded the version telerik.ui.for.aspnet.core.2019.1.220.commercial.zip

and

Telerik.UI.for.AspNet.Core.2019.1.220

as well as the project : rpstrackeraspcore-master.zip

I don't see any updated information on how to use this for the 2026 version of telerik. Also there is no Commercial file listed for 2026 that I could find. Please can you advise??

I followed the steps listed in the video and got a bunch of errors when I tired to install the files on to the project as directed and got a bunch of errors. Example 1

I am using Telerik.UI.for.AspNet.Core (2026.1.212) in a C# net9 application. I am running into issues attempting to create a responsive Form layout for my Form component in the UI for ASP.NET Core library.

My form is being built like:

Html.Kendo().Form<MyFormModel>()
    .Name("MyFormName")
    .FormData(Model.Model)
    .HtmlAttributes(new {@method = "POST" })
    .Layout("grid")        
    .Grid(g => 
        g.Cols(c =>
        {
            c.Add().MaxWidth(1680).Value(6);
            c.Add().MinWidth(1681).Value(12);
        }               
        )
    )
    .Validatable(v =>
    {
        v.ValidateOnBlur(true);
        v.ValidationSummary(true);
        v.ErrorTemplate("<span style='color:red;'>Fill in #=data.field#</span>");
    })
    .Items(i => 
    { 
        //=======================================//= REQUEST INFORMATION                 = //=======================================
        i.AddGroup().Label("Request Information").ColSpan(6).Layout("grid")
        .Grid(g =>        
            g.Cols(c =>
            {
                c.Add().MaxWidth(500).Value(1);
                c.Add().MinWidth(501).Value(12);

            })
        )
        .Items(gi =>
        {
            //Group Items
        });


        //=======================================//= Request/Date Information            =//=======================================
        i.AddGroup()
        .ColSpan(6)
        .Label("Request and Date Information")
        .Layout("grid")
        .Grid(g =>
        {
            g.Cols(c =>
            {
                c.Add().MaxWidth(500).Value(1);
                c.Add().MinWidth(501).Value(2);
            });
        })
        .Items(gi =>
        {
            //Group Items       
        });
})
)                        
        

The image attached shows that the responsive column rules are being converted into css classes like "k-gap-x-[object Object]" instead of "k-grid-cols-12" or "k-grid-cols-6". This behavior happens on the main form and each group within the form. I've also attempted to try setting a column gutter but that also does not convert to a css class properly. I have referenced the documentation and demo page https://www.telerik.com/aspnet-core-ui/documentation/html-helpers/layout/form/responsive and https://demos.telerik.com/aspnet-core/form/responsive-form but the behavior on the demo side does not seem to align with the behavior in my application.

Any insight or thoughts are appreciated!

Using VS2026.

When I clone our project and then try to build it, I get this error:

Unable to load the service index for source https://nuget.telerik.com/v3/index.json. 
Response status code does not indicate success: 401 (Unauthorized).
 
In the "tools -> nuget package manager -> package manager settings -> nuget package manager -> configuration files", I see several nuget.config files.
The first nuget.config in the list is in located in the solution folder.
The second nuget.config in located in the "users\myname\AppData\roaming\nuget\" folder
The second nuget.config contains my nuget.telerik UID and PW. The first nuget.config does not have that info. Not sure if this matters or if I can switch the priority.
Also, I tried downloading my "telerik-license.txt" and placed it in my solution folder. Did not help.
Online it says to add source "https://nuget.telerik.com/v3/index.json" and use telerik UI and PW. Unsure where to do this.
I also removed then added the "Sources" through the VS2026 UI "nuget package manager -> sources", shown here. But I was never asked for a UID and PW as the articles online say would happen.
nuget.org	https://api.nuget.org/v3/index.json
TelerikOnlineFeed	https://nuget.telerik.com/v3/index.json
 
Also, when I open this solution in VS2026, a dialog appears asking to update "Telerik UI for ASP.NET Core version update". 
"Version Update" -> "Please, log in to download the latest version of Telerik UI for ASP.Net Core"
When I click the button, a web page appears saying I was successfully logged into telerik. When I return to VS2026, there is an error:
"Authentication did not succeed. Please try again"
 
How can I resolve this?
 

when am used DropDownTree control i am used below sample format

@(Html.Kendo().DropDownTree()
       .Name("ID")
       .Label(label =>
       {
           label.Content("Select an ID...");
       })
       .DataTextField("Name")
       .DataValueField("id").Value(12)
       .HtmlAttributes(new { style = "width: 100%" })
       .Filter(FilterType.Contains)
       //.LoadOnDemand(true)
       .DataSource(dataSource => dataSource.ServerFiltering(true).Read(read => read.Action("GetLocationListForDDTree", "Home") ) )
   )

when enable loadondemand it works filter but value not show selected . if am command the loadondemand its show the selected value but filter not working . i need both options kindly advice this 

Hello,

is there a possibility to support multitouch input on Pdf Viewer and Image Editor?

Moving and tapping is supported. So I can scroll through the pages for example. But I need to use zoom and pinch gesture for zooming in or out to documents / images also.

As we need to zoom just areas (e.g. maps with geo information) and keep the menus on top, the pages are not user-scalable as a whole:
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1,minimum-scale=1, user-scalable=no,text/html,charset=utf-8">

Is there any workaround to catch the event and set the zoom factor?

And is there a possibility to couple the mouse wheel / double click event to the zoom factor?

Thanks,

Christine

I am attempting to reference some CheckBoxes withing a RadGrid inside a PlaceHolder.

I have a field that I am retrieving called Block that contains a numerice value. Based on the value I am dynamically creating a number of CheckBoxes in a PlaceHolder equal to that value. I have a Button Click method that is trying to reference the CheckBoxes but it is not working correctly.

This line : Dim BlockCheckBox As CheckBox = DirectCast(phBlocksCheckBox.FindControl("BlockCheckBox_" & cbIndex), CheckBox) is not returning a value.

I have a NET core app and calling an external API fropm another site which returns anJSON that looks like this

[
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 1",
    "color": "red",
    "dateInfo": "2026-01-01T00:00:00",
    "consumption": "44.35"
  },
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 1",
    "color": "red",
    "dateInfo": "2026-01-02T00:00:00",
    "consumption": "44.38"
  },
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 1",
    "color": "red",
    "dateInfo": "2026-01-03T00:00:00",
    "consumption": "44.38"
  },
   {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 2",
    "color": "blue",
    "dateInfo": "2026-01-01T00:00:00",
    "consumption": "291.59"
  },
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 2",
    "color": "blue",
    "dateInfo": "2026-01-02T00:00:00",
    "consumption": "293.00"
  },
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 2",
    "color": "blue",
    "dateInfo": "2026-01-03T00:00:00",
    "consumption": "289.21"
  },
 {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 3",
    "color": "yellow",
    "dateInfo": "2026-01-01T00:00:00",
    "consumption": "228.62"
  },
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 3",
    "color": "yellow",
    "dateInfo": "2026-01-02T00:00:00",
    "consumption": "577.15"
  },
  {
    "powerDeviceName": "Datarack",
    "powerDeviceUnitName": "Datarack Fas 3",
    "color": "yellow",
    "dateInfo": "2026-01-03T00:00:00",
    "consumption": "295.35"
  }
]

From this I want to create a chart with series that matches the "powerDeviceUnitName" values (with the color from JSON) and the axis will list all dates in dateInfo The "value" for the chart is "consumption"

I didn't thought this should be any hard issue, but I can't find any example on Teleriks demos that have external JSON?

Anyone that can help me in the right direction?

Regards Pelle