GridViewDataControlExport(Stream stream, GridViewExportOptions options) Exception: Object reference not set to an instance of an object

[Paul]

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

[Maya]

Hello Paul,

I tried to reproduce the issue you reported, but without any success. Could you run through the project attached and let me know whether I am missing anything ? 

Regards,
Maya
Telerik

[Paul]

Thank you for your answer.

So ... If you you remove the data of the grid (the grid will be empty) you will get the Exception.

 

public static ObservableCollection<Club> GetClubs()
        {
            return new ObservableCollection<Club>();
        }

[Maya]

Hello Paul,

I tried the same functionality with empty grid, but I am still not able to reproduce the exception. Which version are you working with ? If it is not the current official one (Q1 2015 SP1), could you try with it ? 

Regards,
Maya
Telerik

[Paul]

v2013.1.422.45

[Maya]

Hi Paul,

Actually, this version is from around 2 years ago and unfortunately, even if there is an exception in the code, there is no much that we can do.  My recommendation is to download our current official version and give it a try instead.

Regards,
Maya
Telerik