@(Html.Kendo().Grid<MyModel>()
  .Name("mygriddata")
  .Columns(column =>
  {
      column.Bound(model => model.MyData).Title("No.").....
  })
    .Pageable(x => x.PageSizes(true).ButtonCount(3).Responsive(false))
    .AutoBind(false)
    .Filterable()
    .Sortable(x => x.Enabled(true))
    .Resizable(resizable => resizable.Columns(true))
    .Scrollable(x => x.Height("auto"))
    .PersistSelection()
    .HtmlAttributes(new { style = "height: 50vh; margin-left:10px", @class = "form-group" })
    .NoRecords()
    .DataSource(dataSource => dataSource
        .Ajax()
        .ServerOperation(true)
        .Model(model =>
        {
            model.Id(item => item.ID);
        })
        .Read(read => read.Action("MyActionMethod", "MyController"))
    )
)

public async Task<JsonResult> MyActionMethod([DataSourceRequest] DataSourceRequest request)
{
    var data = await _service.GetData();
     var model = data.Select((item, index) => new MyModel
                    {
                        MyData = ......
                    });

    return new JsonResult { Data = model.ToDataSourceResultAsync(request), MaxJsonLength = int.MaxValue, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}

Message: The asynchronous action method 'MyActionMethod' returns a Task, which cannot be executed synchronously.

public ActionResult GetDoubleCombinations(Telerik.Web.Spreadsheet.Workbook jsonData, int id)
{

    foreach (var sheet in jsonData.Sheets)
    {
        var columnCount = sheet.Columns.Count;
        var rowCount = sheet.Rows.Count;

        for (int i = 2; i < columnCount; i++)
        {
            var expressionTop = expressionService.GetExpressionByName(sheet.Rows[1].Cells[i].Value.ToString(), id);
            var parameterTop = expressionTop.FK_ParameterID;

            for (int j = 2; j < rowCount; j++)
            {
                var expressionLeft = expressionService.GetExpressionByName(sheet.Rows[j].Cells[1].Value.ToString(), id);
                var parameterLeft = expressionLeft.FK_ParameterID;

                if (parameterTop == parameterLeft)
                {
                    var position = sheet.Rows[i].Cells[j];
                    position.Enable = false;
                    position.Background = "#d3d3d3";
                }
            }

        }
        
    }
    return Json(new { success = true, data = jsonData });
}

function getDoubleCombinations() {

    var spreadsheet = $("#matrix").data("kendoSpreadsheet");
    const urlParams = new URLSearchParams(window.location.search);
    const id = urlParams.get('analysisId');

    $.ajax({
        url: "@Url.Action("GetDoubleCombinations", "Matrix")",
        data: JSON.stringify({
            jsonData: spreadsheet.toJSON(),
            id: id
        }),
        contentType: "application/json",
        type: "POST",
        success: function (response) {
            spreadsheet.fromJSON(response.data);
        },
        error: function () {
            alert("Error loading data.");
        }
    });
}

@model Telerik.Web.Spreadsheet.Workbook
@(Html.Kendo().Spreadsheet()
    .Name("matrix")
    .HtmlAttributes(new { style = "width:100%" })
    .BindTo(Model)
    .Toolbar(t =>
    {
        t.Home(h =>
        {
            h.Clear();
            h.ExportAs();
        });
        t.Data(false);
        t.Insert(false);
    })
)

public ActionResult ChartTMS(DateTime? fromDate, DateTime? toDate, string unit = "gm")
        {
            fromDate = fromDate?.Date;
            toDate = toDate.HasValue ? toDate.Value.Date.AddDays(1).AddTicks(-1) : DateTime.Today;
 
            if (!fromDate.HasValue || !toDate.HasValue)
            {
                fromDate = DateTime.Today.AddDays(-6);
                toDate = DateTime.Today;
            }
 
            var allMeasurements = (
                from m in db.Target_Measurement_History.AsNoTracking()
                where m.Measurement_Record_Date >= fromDate.Value && m.Measurement_Record_Date <= toDate.Value
&& m.Target_Lot_Profile != null
&& m.Target_Lot_Profile.Target_Item != null
&& m.Target_Lot_Profile.Target_Item.Target_Manufacturer != null
                select new MeasurementDataViewModel
                {
                    Measurement_Record_Date = m.Measurement_Record_Date,
                    Pt_Remaining_Gms = m.Pt_Remaining_Gms,
                    Ru_Remaining_Gms = m.Ru_Remaining_Gms,
                    Manufacturer = m.Target_Lot_Profile.Target_Item.Target_Manufacturer,
                }).ToList();
 
            var manufacturers = allMeasurements.Select(m => m.Manufacturer).Distinct();
            var colorMap = new Dictionary<string, string>();
            Random rand = new Random();
 
            foreach (var manufacturer in manufacturers)
            {
                colorMap[manufacturer] = $"#{rand.Next(0x1000000):X6}";
            }
 
            var groupedData = allMeasurements
                .GroupBy(m => new { m.Measurement_Record_Date.Date, m.Manufacturer })
                .Select(group => new MeasurementDataViewModel
                {
                    Measurement_Record_Date = group.Key.Date,
                    Pt_Remaining_Gms = group.Sum(item => item.Pt_Remaining_Gms),
                    Ru_Remaining_Gms = group.Sum(item => item.Ru_Remaining_Gms),
                    Manufacturer = group.Key.Manufacturer,
                    Color = colorMap[group.Key.Manufacturer]
                })
                .OrderBy(g => g.Measurement_Record_Date)
                .ThenBy(g => g.Manufacturer)
                .ToList();
 
            const float gramsPerTroyOunce = 31.1035f;
 
            if (unit == "t oz")
            {
                foreach (var item in groupedData)
                {
                    if (item.Pt_Remaining_Gms.HasValue)
                        item.Pt_Remaining_Gms = item.Pt_Remaining_Gms.Value / gramsPerTroyOunce;
 
                    if (item.Ru_Remaining_Gms.HasValue)
                        item.Ru_Remaining_Gms = item.Ru_Remaining_Gms.Value / gramsPerTroyOunce;
                }
            }
 
            ViewBag.fromDate = fromDate;
            ViewBag.toDate = toDate;
            ViewBag.Unit = unit;
 
            return View(groupedData);
        }

    public class MeasurementDataViewModel
    {
        public DateTime Measurement_Record_Date { get; set; }
        public float? Pt_Remaining_Gms { get; set; }
        public float? Ru_Remaining_Gms { get; set; }
        public string Manufacturer { get; set; }
        public string Color { get; set; }
    }

[
    {
        "Measurement_Record_Date": "/Date(1542823200000)/",
        "Pt_Remaining_Gms": 4370,
        "Ru_Remaining_Gms": 5621,
        "Manufacturer": "JX Nippon"
    },
    {
        "Measurement_Record_Date": "/Date(1542823200000)/",
        "Pt_Remaining_Gms": 4571,
        "Ru_Remaining_Gms": 4295,
        "Manufacturer": "Kojundo/Mitsui"
    },
    {
        "Measurement_Record_Date": "/Date(1543168800000)/",
        "Pt_Remaining_Gms": 1785,
        "Ru_Remaining_Gms": 7086,
        "Manufacturer": "JX Nippon"
    },
    {
        "Measurement_Record_Date": "/Date(1543255200000)/",
        "Pt_Remaining_Gms": 36432,
        "Ru_Remaining_Gms": 41800,
        "Manufacturer": "Kurt J. Lesker"
    },
    {
        "Measurement_Record_Date": "/Date(1543428000000)/",
        "Pt_Remaining_Gms": 76360,
        "Ru_Remaining_Gms": 74687,
        "Manufacturer": "Kurt J. Lesker"
    },
    {
        "Measurement_Record_Date": "/Date(1543428000000)/",
        "Pt_Remaining_Gms": 11138,
        "Ru_Remaining_Gms": 9686,
        "Manufacturer": "Materion"
    },
    {
        "Measurement_Record_Date": "/Date(1543428000000)/",
        "Pt_Remaining_Gms": 1329,
        "Ru_Remaining_Gms": 4796,
        "Manufacturer": "Mitsubishi"
    }
]

@using Kendo.Mvc.UI
@using System.Web.Mvc
@using System.Web.Mvc.Html
@using Kendo.Mvc.Extensions
@model IEnumerable<TMS_RND.Controllers.MeasurementDataViewModel>
@using System.Web.Helpers
 
@{
    ViewBag.Title = "Chart";
    Layout = "~/Views/Shared/_Layout.cshtml";
 
    DateTime startDate = ViewBag.fromDate ?? DateTime.Today.AddDays(-6);
    DateTime endDate = ViewBag.toDate ?? DateTime.Today;
    string currentUnit = ViewBag.Unit ?? "gm";
    var manufacturers = Model
        .GroupBy(m => m.Manufacturer)
        .Select(g => new
        {
            Manufacturer = g.Key,
            Color = g.First().Color
        })
        .ToList();
}
 
 
<div class="demo-section wide">
<div style="display: flex; justify-content: space-between; align-items: center;">
<div>
            From: @(Html.Kendo().DatePicker().Name("fromDate").Value(startDate.ToString("yyyy-MM-dd")))
            To: @(Html.Kendo().DatePicker().Name("toDate").Value(endDate.ToString("yyyy-MM-dd")))
<button id="refreshChart">Refresh Chart</button>
<button id="clearFilter">Clear</button>
<button id="toggleUnit">@(currentUnit == "gm" ? "Switch to Troy oz" : "Switch to gm")</button>
</div>
<div>
<button class="tab" id="totalPoolTab">Total Pool</button>
<button class="tab" id="tmsTab" style="background-color: lightblue;">TMS</button>
</div>
<div>
            @foreach (var manufacturer in manufacturers)
            {
<span style="color:@manufacturer.Color">@manufacturer.Manufacturer</span>
            }
</div>
</div>
<div id="chartContainer">
        @(Html.Kendo().Chart(Model)
            .Name("chart")
            .Title("Historical Pool Data")
            .HtmlAttributes(new { style = "height: 400px;" })
            .Legend(legend => legend.Position(ChartLegendPosition.Bottom))
            .SeriesDefaults(seriesDefaults => seriesDefaults.Line().Stack(false))
            .Series(series => {
                foreach (var manufacturer in manufacturers)
                {
                    var manufacturerData = Model.Where(m => m.Manufacturer == manufacturer.Manufacturer).ToList();
                    series.Line(manufacturerData.Select(m => m.Pt_Remaining_Gms))
                          .Name("Pt - " + manufacturer.Manufacturer)
                          .Color(manufacturer.Color)
                          .Visible(true)
                          .Labels(labels => labels.Visible(true).Format("{0:N2} " + currentUnit));
                    series.Line(manufacturerData.Select(m => m.Ru_Remaining_Gms))
                          .Name("Ru - " + manufacturer.Manufacturer)
                          .Color(manufacturer.Color)
                          .Visible(false)
                          .Labels(labels => labels.Visible(true).Format("{0:N2} " + currentUnit));
                }
            })
            .CategoryAxis(axis => axis.Categories(Model.Select(m => m.Measurement_Record_Date.ToString("dd MMM yyyy")).Distinct()))
            .ValueAxis(axis => axis.Numeric()
                .Line(line => line.Visible(false))
                .Title("Weight (" + currentUnit + ")"))
            .Tooltip(tooltip => tooltip.Visible(true).Format("{0:N2} " + currentUnit))
        )
</div>
</div>
 
<script>
    $(document).ready(function () {
        function toISOStringWithMidday(date) {
            var localDate = new Date(date);
            localDate.setHours(12, 0, 0, 0);
            var offset = localDate.getTimezoneOffset() * 60000;
            var localMidday = new Date(localDate.getTime() - offset);
            return localMidday.toISOString();
        }
 
        $("#refreshChart").click(function () {
            refreshChart();
        });
 
        $("#toggleUnit").click(function () {
            var newUnit = '@currentUnit' == 'gm' ? 't oz' : 'gm';
            refreshChart(newUnit);
        });
 
        $("#clearFilter").click(function () {
            window.location.href = '@Url.Action("ChartTMS", "Target_Measurement_History")';
        });
 
        function refreshChart(newUnit) {
            var selectedFromDate = $("#fromDate").data("kendoDatePicker").value();
            var selectedToDate = $("#toDate").data("kendoDatePicker").value();
            var unitParam = newUnit || '@currentUnit';
 
            if (selectedFromDate && selectedToDate) {
                var difference = Math.abs(selectedToDate.getTime() - selectedFromDate.getTime());
                if (difference > 7 * 24 * 60 * 60 * 1000) {
                    alert("Please select a date range within 7 days.");
                    return;
                }
 
                var fromDateStr = toISOStringWithMidday(selectedFromDate);
                var toDateStr = toISOStringWithMidday(selectedToDate);
 
                window.location.href = '@Url.Action("ChartTMS", "Target_Measurement_History")' + '?fromDate=' + fromDateStr + '&toDate=' + toDateStr + '&unit=' + unitParam;
            } else {
                alert("Please select both from and to dates.");
            }
        }
 
        $("#totalPoolTab").click(function() {
            window.location.href = '@Url.Action("Chart", "Target_Measurement_History")';
        });
 
        $("#tmsTab").click(function() {
            window.location.href = '@Url.Action("ChartTMS", "Target_Measurement_History")';
        });
 
        $("#tmsTab").css("background-color", "lightblue");
 
        $(".tab").click(function() {
            $(".tab").css("background-color", "");
            $(this).css("background-color", "lightblue");
        });
    });
</script>