<script>
      function onPdfViewerComplete(e){
        debugger;
        try {
                const scroller = e.sender._scroller;
                const scrollPosition = scroller.scrollTop;
                const maxScrollPosition = scroller.scrollHeight - scroller.clientHeight;

            scroller.bind('scroll', ()=> {
                if (scrollPosition >= maxScrollPosition) {
                    alert("Scrolled to the bottom of the PDF");
                }
            });
        } catch(e) {
            console.error("error", e);
        }
    }
</script>

                .Pdf(pdf => pdf
                    .FileName("BidAwards.pdf")
                    .AllPages()
                    .PaperSize("A4")
                    .Landscape()
                    .AvoidLinks()
                )
                .DataSource(dataSource => dataSource
                    .Ajax()
                    .PageSize(100)
                    .Events(events => events.Error("error_handler"))
                    .Model(model => model.Id(col => col.BidId))
                    .Read(read => read.Action("BidAwardGridData", "Reports", Model))
                    .Group(groups => groups.Add(col => col.GroupValue))

                )

        function previewPdf(){
            //I need to pass this doc object to the endpoint
            //var doc = {
            //    case: { caseNumber: 'A12345' },
            //    title: 'Test Doc',
            //    body: $('#Content').data("kendoEditor").value() //getting content from a kendo editor the user is filling out
            //};

            // Create a viewer if you do not have one already.
            var pdfViewer = $("#pdf-viewer").data("kendoPDFViewer");
            if(!pdfViewer){
                pdfViewer = $("#pdf-viewer").kendoPDFViewer({
                    pdfjsProcessing: {
                        file: ""
                    },
                    width: 900,
                    height: window.innerHeight - 150
                }).data("kendoPDFViewer");
            }
            var pdfHandlerUrl = '@Url.Action("GetCourtDocumentPdfBytes", "CourtDocuments")';

                 // I was hoping to make an AJAX call like this and then somehow set the file to the PDF viewer but no luck.
                  //$.ajax({
                  //    type: "POST",
                  //    url: pdfHandlerUrl,
                  //    data: JSON.stringify(doc),
                  //    contentType: "application/json",
                  //    success: function(response) {
                  //      // Use the response (which should be a byte array of the PDF) to update the PDF viewer
                  //      pdfViewer.fromFile(response); // this doesn't work so clearly not setting the right type here.
                  //    }
                  //});

            // Build the desired URL to point to your handler that will return the PDF.
                  
            pdfViewer.fromFile(pdfHandlerUrl); //this is working fine just for a GET endpoint

            $("#wndPdfPreview").kendoWindow({
                modal: true,
                width: 1000,
                height: window.innerHeight - 100
            });
            $("#wndPdfPreview").data("kendoWindow").center().open();           
        }

//this approach is working.

public async Task<FileStreamResult> GetCourtDocumentPdfBytes()
        {
            CourtDocument doc = new CourtDocument { Body = "the Body", Title = "the title", Case = new Case { CaseNumber = "2018123CA01" } };
            string html = await this.RenderViewToString("_JudicialOrder", doc, true);
            var bytes = await _pdfService.CreateFromHtml(html, doc.Case.CaseNumber);

            Stream stream = new MemoryStream(bytes);
            return new FileStreamResult(stream, "application/pdf");
            //return File(bytes, "application/pdf", "test.pdf");
        }

//This is more of what I would need.
public async Task<IActionResult> GetCourtDocumentPdfBytes([FromBody] CourtDocument doc)
        {
            string html = await this.RenderViewToString("_JudicialOrder", doc, true);
            var bytes = await _pdfService.CreateFromHtml(html, doc.Case.CaseNumber);

            Stream stream = new MemoryStream(bytes);
            //return new FileStreamResult(stream, "application/pdf");
            return File(bytes, "application/pdf", "test.pdf"); // not sure what to return here to load the pdfViewer from it in the client.
        }

// Create a viewer if you do not have one already.
        var pdfViewer = $("#pdfViewer").data("kendoPDFViewer");
        if (!pdfViewer) {
            pdfViewer = $("#pdfViewer").kendoPDFViewer({
                pdfjsProcessing: {
                    file: ""
                },
                width: "100%",
                height: 500
            }).data("kendoPDFViewer");
        };

        // Build the desired URL to point to your handler that will return the PDF.
        var pdfHandlerUrl = "/Home/getBlob/" + selectedRows.BlobID;

        // Make the PDFViewer load the designated file.
        pdfViewer.fromFile(pdfHandlerUrl);

var stream = new MemoryStream();
await file.DownloadToAsync(stream);
  stream.Position = 0;
                   
 return new FileStreamResult(stream, "application/pdf");