Hi Hristo,

Thanks for your help. I was able to export using your modified code.  As you already mentioned there were few issues with the code. Here is the modified version.

function exportGrid() {
                //$.ig.GridExcelExporter.export($("#igdataGrid"), { fileName: "Manage_Generator_Mapping" }, {
                //    rowExported: function (sender, args) {
                        
                    //}
                //});              
                var workbook = new $.ig.excel.Workbook($.ig.excel.WorkbookFormat.excel2007);
                var worksheet = workbook.worksheets().add('Sheet1');
                //var displayOptions = new $.ig.excel.DisplayOptions().showExpansionIndicatorBelowGroupedRows(true);
               // worksheet.displayOptions. = displayOptions;
                //var rowBase = new $.ig.excel.RowColumnBase();
                var xlRowIndex = 0;
                var headersTable = $("#igdataGrid").igGrid("headersTable")[0];
                for (var headerRowIndex = 0;
                headerRowIndex < headersTable.rows.length - 2;
                headerRowIndex++, xlRowIndex++) {
                    var headerRow = headersTable.rows[headerRowIndex];
                    var xlHeaderRow = worksheet.rows(xlRowIndex);
                    var computedStyle = window.getComputedStyle(headerRow);
                    var xlColorInfo = new $.ig.excel.WorkbookColorInfo(computedStyle.color);
                    xlHeaderRow.cellFormat().font().colorInfo(xlColorInfo);
                    for (var headerCellIndex = 0;
                    headerCellIndex < headerRow.cells.length-1;
                    headerCellIndex++) {
                        var headerCell = headerRow.cells[headerCellIndex + 1];
                         worksheet.columns(headerCellIndex).setWidth(
                         headerCell.offsetWidth, $.ig.excel.WorksheetColumnWidthUnit.pixel);
                        var xlHeaderCell = xlHeaderRow.cells(headerCellIndex);
                         var computedStyle = window.getComputedStyle(headerCell);
                         xlHeaderCell.cellFormat().fill(
                          $.ig.excel.CellFill.createSolidFill(computedStyle.backgroundColor));
                        xlHeaderCell.value($(headerCell).text());
                    }
                }
                var rows = $("#igdataGrid").igGrid("rows");
                
                var childGridTable, childHeaderRow;
                for (var dataRowIndex = 0;
                dataRowIndex < rows.length;
                dataRowIndex++, xlRowIndex++) {
                    var dataRow = rows[dataRowIndex];
                    var xlRow = worksheet.rows(xlRowIndex);
                    //rowBase.index = xlRowIndex;
                    //rowBase.outlineLevel(1);
                    xlRow.outlineLevel(0);
                    for (var dataCellIndex = 0;
                    dataCellIndex < dataRow.cells.length-1;
                    dataCellIndex++) {
                        var dataCell = dataRow.cells[dataCellIndex+1];
                        xlRow.setCellValue(dataCellIndex, $(dataCell).text());
                    }
                    
                    //expand the first child grid to get the headers name.
                    var parentGrid = $("#igdataGrid").igHierarchicalGrid("rootWidget"),
                        rowDomElement = parentGrid.rowAt(dataRowIndex);
                    $("#igdataGrid").igHierarchicalGrid("expand", rowDomElement);
                    childGridTable = $("#igdataGrid").igHierarchicalGrid("allChildren")[dataRowIndex];
                    //childHeaderRow = childHeadersTable.find("thead").find('span.ui-iggrid-headertext');                                           
                                        
                    //extract all the childgrid data
                    //var childRows = $("#igdataGrid").find("table[data-childgrid=true]").data().igGrid.dataSource.data();
                    
                    //$.ig.excel.DisplayOptions.showExpansionIndicatorBelowGroupedRows(true);
                    var childHeadersTable = $(childGridTable).igGrid("headersTable")[0];
                    childRows = $(childGridTable).igGrid("rows");
 
                    if (childRows.length > 0) {                        
                        xlRowIndex++;
                        //write the child header row                        
                        var headerRow = childHeadersTable.rows[0];
                        var xlHeaderRow = worksheet.rows(xlRowIndex);
                        //rowBase.index = xlRowIndex;
                        //rowBase.outlineLevel(2);
                        xlHeaderRow.outlineLevel(1);
                        var computedStyle = window.getComputedStyle(headerRow);
                        var xlColorInfo = new $.ig.excel.WorkbookColorInfo(computedStyle.color);
                        xlHeaderRow.cellFormat().font().colorInfo(xlColorInfo);
                        for (var headerCellIndex = 0;
                        headerCellIndex < headerRow.cells.length;
                        headerCellIndex++) {
                            var headerCell = headerRow.cells[headerCellIndex];
                            //worksheet.columns(headerCellIndex + 1).setWidth(
                            //headerCell.offsetWidth, $.ig.excel.WorksheetColumnWidthUnit.pixel);
                            var xlHeaderCell = xlHeaderRow.cells(headerCellIndex + 1);
                            var computedStyle = window.getComputedStyle(headerCell);
                            xlHeaderCell.cellFormat().fill(
                            $.ig.excel.CellFill.createSolidFill(computedStyle.backgroundColor));
                            xlHeaderCell.value($(headerCell).text());
                        }
                        
 
                        xlRowIndex++;
                        for (var index = 0;
                            index < childRows.length;
                            index++, xlRowIndex++) {
                            var childRow = childRows[index];
                            var xlRow = worksheet.rows(xlRowIndex);
                            //rowBase.index = xlRowIndex;
                            //rowBase.outlineLevel(2);
                            xlRow.outlineLevel(1);
                            for (var childGridCellIndex = 0;
                            childGridCellIndex < childRow.cells.length;
                            childGridCellIndex++) {
                                var dataCell = childRow.cells[childGridCellIndex];
                                xlRow.setCellValue(childGridCellIndex + 1, $(dataCell).text());
                            }
                        }
                    }
 
                    $("#igdataGrid").igHierarchicalGrid("collapse", rowDomElement);
                }
                workbook.save({ type: 'blob' }, function (data) {
                    saveAs(data, "Manage_Generator_Mapping.xlsx");
                }, function (error) {
                    alert('Error exporting: : ' + error);
                });}

Never mind, I found the solution. It was the script manager which was causing this. 

Hi,

I made changes suggested by you and it worked on one page. But on the other page where I have same hierarchical grid, it is throwing some exception on 

var workbook = new $.ig.excel.Workbook($.ig.excel.WorkbookFormat.excel2007);
var worksheet = workbook.worksheets().add('Sheet1');  //Error on this line -- Uncaught Sys.ParameterCountException: Sys.ParameterCountException: Parameter count mismatch.

Please help me out here.

Thanks,

Hiren. 

Thank you for your feedback, I am glad you have managed to resolve your issue. Please let me know if I may be of any further assistance to you.