Before export to Excel we add aggregate function:
var sumFunction = new CountFunction()
{
ResultFormatString = " ({0} items): "
};
column.AggregateFunctions.Add(sumFunction);
Export functionality:
var options = new GridViewExportOptions
{
Format = ExportFormat.ExcelML,
ShowColumnHeaders = true,
ShowColumnFooters = true,
ShowGroupFooters = true,
Encoding = Encoding.UTF8
};
var fileToExportTo = exportFileInfo.FullName;
using (FileStream fs = new FileStream(fileToExportTo, FileMode.OpenOrCreate))
{
gridControl.Export(fs, options);
}
Exception: Object reference not set to an instance of an object.
at Telerik.Windows.Controls.GridViewBoundColumnBase.<>c__DisplayClass18.<Telerik.Windows.Controls.IExportableColumn.GetCellContent>b__12(AggregateFunction f) in c:\TB\221\WPF_Scrum\Current_HotFix\Sources\Controls\GridView\GridView\GridView\Columns\GridViewBoundColumnBase.cs:line 55
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at Telerik.Windows.Controls.GridViewBoundColumnBase.Telerik.Windows.Controls.IExportableColumn.GetCellContent(Object parameter) in c:\TB\221\WPF_Scrum\Current_HotFix\Sources\Controls\GridView\GridView\GridView\Columns\GridViewBoundColumnBase.cs:line 56
at Telerik.Windows.Controls.GridViewExportWriter.RenderHeaderOrFooterCells(ExportElement element, Object context) in c:\TB\221\WPF_Scrum\Current_HotFix\Sources\Controls\GridView\GridView\GridView\Exporting\GridViewExportWriter.cs:line 692
at Telerik.Windows.Controls.GridViewExportWriter.RenderFooterRow() in c:\TB\221\WPF_Scrum\Current_HotFix\Sources\Controls\GridView\GridView\GridView\Exporting\GridViewExportWriter.cs:line 535
at Telerik.Windows.Controls.GridViewExportWriter.Render() in c:\TB\221\WPF_Scrum\Current_HotFix\Sources\Controls\GridView\GridView\GridView\Exporting\GridViewExportWriter.cs:line 101
at Telerik.Windows.Controls.GridView.GridViewDataControl.Export(Stream stream, GridViewExportOptions options) in c:\TB\221\WPF_Scrum\Current_HotFix\Sources\Controls\GridView\GridView\GridView\Exporting\GridViewDataControl.Exporting.cs:line 31