I just finished a rather painful journey into putting together a demo to be able to use the Telerik Grid on a Razor page at all and then how to add checkboxes to it. Sounds easy, but it was not. Just try to find useful (or in some cases any) documentation on this stuff. 

Start with the https://github.com/telerik/ui-for-aspnet-core-examples solution and use the Kendo.Examples.RazorPages project. I added a Mange folder under pages and a "Lab" page under that (Lab.cshtml / Lab.cshtml.cs) - here is the code and my discussion follows:

I’ve a Razor Page project with Telerik ASP.NET Core Calender and a database in the back-end. In the Calender I can create new schedules that saves to the database and also read them to populate. For every schedule I would like to add what shift I should be related to so I’ve added a resource and if I create it as a new list it works fine but I can’t figure out how to populate from a table in the database. It feels that I’ve tried million ways now without success.
In this way it works:
                     .Resources(resource =>
                        {
                            resource.Add(m => m.ShiftID)
                            .Name("ShiftList")
                            .Title("Skift") 
                            .DataTextField("Text")
                            .DataValueField("Value")
                            .DataColorField("Color")

                            .BindTo(new[] {
                                new { Text = "fm-skift", Value = 1, Color = "#f8a398" } ,
                                new { Text = "em-skift", Value = 2, Color = "#51a0ed" } ,
                                new { Text = "Natt-skift", Value = 3, Color = "#56ca85" },
                                new { Text = "FM-skift", Value = 4, Color = "#c39bd3" },
                                new { Text = "EN-skift", Value = 5, Color = "#f1c40f" }
                            })
                            ;
                        })

But how can I populate from the database? All the Examples I can find are using MVC and not “true” Razor Pages.

on the model page I've created a list from the database that contains, Value, Textand Color, but I can't use it with Telerik Resources.

While putting together my first app, I am loading a grid via javascript, populating the grid with Json data only after a number of other inputs are gathered from the user. While doing this, I omitted the .Read method on the datasource.  I was noticing http 400 errors everytime this page loaded.  Initially thought I was having issues with the Forgerytoken, but after trial-and-error, comparing to another sample page, I decided to stub in a .Read method and handler in the controller, and the http 400 errors stopped.  So I suppose my question is this - is a .Read method required, even if it will never be used?

See attached files, that show both screenshots of network traffic from the chrome debugger console.  Notice the last request in the stack in each case.

In this dojo I want to have a button to select the next and previous tabs(wizard navigation). The buttons work if the user clicks them slowly.

If the next button is clicked say 5 times rapidly, the tabstrip will only select up until the 2nd or 3rd tab instead of going all the way to the end.

I am using the asp.net core version of kendo but the jquery version is easier to show in the dojo and represents my problem.

https://dojo.telerik.com/EWALijil

Is there a way outside of disabling the button/debouncing/ or timeouts to get the tabstrip to queue any selects and use the final?

I insert a image to the sheet, and transform sheet to datauri format. I get a error message.

function SaveElnFile(e) {
        var spreadSheet = GetSpreadsheet("ElnMain");
        var sheet = spreadSheet.activeSheet();
        spreadSheet.bind("excelExport", function (e) {
            var fileName = "ElnTemplate/" + GetDateTimeString() + ".xlsx";
            e.workbook.fileName = fileName;
            var workbook = new kendo.ooxml.Workbook({
                sheets: e.workbook.sheets
            });

            workbook.toDataURLAsync().then(function (dataURL) {
                xxxxxx....
            });
                e.preventDefault();
        });
        spreadSheet.saveAsExcel();
    }

I don't think I'm alone in saying that it would be nice to see better docs, maybe even an entire separate section for this library that was Raorpages-specific.  

Would be nice to see such things as:
- Client template examples
- Different ways of loading & customizing the grid
- Common problems and their solutions

I recently upgraded my project to ASP NET Core 3.2 and now my grids are returning undefined.  I've found a couple threads about this, but nothing that has worked for me so far.  I have an enumerable defined object that I'm creating in my AJAX LoadData method to load my data and returning.  What am I doing wrong?

index.cshtml

<ejs-grid id="Grid" allowPaging="true" allowSorting="true" allowFiltering="true">
    <e-data-manager url="/Routes/LoadData" updateUrl="/Routes/UpdateData" adaptor="UrlAdaptor"></e-data-manager>
    <e-grid-columns>
        <e-grid-column field="Name" headerText="Name" allowSorting="true"></e-grid-column>
        <e-grid-column field="Frequency.Name" headerText="Frequency" type="string"></e-grid-column>
        <e-grid-column field="DayOfWeek.Name" headerText="Day" type="string"></e-grid-column>
        <e-grid-column field="TimeOfDay.TimeString" headerText="Time"></e-grid-column>
        <e-grid-column field="RouteId" headerText="" template="#edittemplate"></e-grid-column>
    </e-grid-columns>
</ejs-grid>

<script id="edittemplate" type="text/x-template">
    <div>
        <a rel='nofollow' href="/Routes/Edit/${RouteId}">Edit</a>&nbsp;|&nbsp;
        <a rel='nofollow' href="/Routes/Details/${RouteId}">Details</a>&nbsp;|&nbsp;
        <a rel='nofollow' href="/Routes/Delete/${RouteId}">Delete</a>&nbsp;
    </div>
</script>

Controller

        public IActionResult LoadData([FromBody]DataManagerRequest dm)
        {
            var sa = new JsonSerializerSettings();
            IEnumerable<Route> DataSource = _context.Route
                .Include(r => r.DayOfWeek)
                .Include(r => r.Frequency)
                .Include(r => r.TimeOfDay)
                .ToList();
            DataOperations operation = new DataOperations();
            if (dm.Search != null && dm.Search.Count > 0)
            {
                DataSource = operation.PerformSearching(DataSource, dm.Search);  //Search
            }
            if (dm.Sorted != null && dm.Sorted.Count > 0) //Sorting
            {
                DataSource = operation.PerformSorting(DataSource, dm.Sorted);
            }
            if (dm.Where != null && dm.Where.Count > 0) //Filtering
            {
                DataSource = operation.PerformFiltering(DataSource, dm.Where, dm.Where[0].Operator);
            }
            int count = DataSource.Cast<Route>().Count();
            if (dm.Skip != 0)
            {
                DataSource = operation.PerformSkip(DataSource, dm.Skip);         //Paging
            }
            if (dm.Take != 0)
            {
                DataSource = operation.PerformTake(DataSource, dm.Take);
            }

            return Json(new { result = DataSource, count = _context.Route.Count() });
        }

Have a razorpages app started and several areas of a view have various dropdowns etc that gather a users selections.  These selections are then used as inputs to grab data for a grid.  Ok, easy enough, my example is working so far.  However, so far I have only got to the point of LOADING my grid, now I need to handle updates/deletes etc.

Im looking over the examples, both frm the kendo project template and from this github project
https://github.com/telerik/ui-for-aspnet-core-examples/blob/master/Kendo.Examples.RazorPages/Kendo.Examples.RazorPages/Pages/Grid/GridCrudOperations.cshtml

Ok, some general questions and observations:

(1) These examples assume that criteria for getting the grid data is known at execution time.  In my case I need to gather several inputs before fetching the data for the grid.  Im doing this now, then loading the grid with json and javascript and it works.  However, now I need to handle updating/deleting etc
(2) What is the purpose of the .Data methods on the Datasource crud methods eg. and where is this Data method in the docs as used here?

(3) If I want to handle "batch" editing, AND I load the Dataset via JSON with javascript, how then does the .Read and other datasource method(s) need to change?
eg.  this example ,
https://demos.telerik.com/aspnet-core/grid/editing

so to load the product grid then