ClosedXML - Creating multiple pivot tables

Question

I am trying to export some data to an excel sheet S1 whose data would be shown as Pivoted views in the next two sheets S2 and S3. I am able to create a single pivot and it works perfect. But when I create two pivots, the consequent Excel file renders as corrupt.

By corrupt I mean,

On clicking yes, I get this -

Here is the code I am using to create the pivots -

using XL = ClosedXML.Excel;
...
XL.XLWorkbook wb = new XL.XLWorkbook();
dsData = Session["ExportData"] as DataSet;

var sheet1 = wb.Worksheets.Add("output table");
sheet1.Cell(1, 1).InsertTable(dsData.Tables[0], "output table", true);

// sheet1 is the reference sheet S1
var dataRange = sheet1.RangeUsed();

// First Pivot
XL.IXLWorksheet ptSheet1 = wb.Worksheets.Add("S2");

var pt1 = ptSheet1.PivotTables.AddNew("PivotTable1", ptSheet.Cell(3, 1), dataRange);


pt1.ReportFilters.Add("CX");

pt1.RowLabels.Add("C1");
pt1.RowLabels.Add("C2");
pt1.RowLabels.Add("C3");
pt1.RowLabels.Add("C4");

pt1.ColumnLabels.Add("CL1");
pt1.ColumnLabels.Add("CL2");
pt1.ColumnLabels.Add("CL3");

pt1.Values.Add("V").SummaryFormula = XL.XLPivotSummary.Sum;


// Second Pivot
XL.IXLWorksheet ptSheet2 = wb.Worksheets.Add("S3");

var pt2 = ptSheet2.PivotTables.AddNew("PivotTable2", ptSheet1.Cell(3, 1), dataRange);

pt2.ReportFilters.Add("QQ");

pt2.RowLabels.Add("C1");
pt2.RowLabels.Add("C2");

pt2.ColumnLabels.Add("CL1");
pt2.ColumnLabels.Add("CL2");
pt2.ColumnLabels.Add("CL3");

pt2.Values.Add("V").SummaryFormula = XL.XLPivotSummary.Sum;

C1, C2, C3. C4 and V are the column names in my reference sheet S1.

Answer 1

Try this modification. I made a note where I added an additional line. Also, I think the AddNew() method may have had the wrong worksheet reference? You may have been trying to add a pivot table on top of another one. That may have been the real issue rather than the additional line I added.

using XL = ClosedXML.Excel;
...
XL.XLWorkbook wb = new XL.XLWorkbook();
dsData = Session["ExportData"] as DataSet;
var sheet1 = wb.Worksheets.Add("output table");
sheet1.Cell(1, 1).InsertTable(dsData.Tables[0], "output table", true);

// sheet1 is the reference sheet S1
var dataRange = sheet1.RangeUsed();
PivotCache cache = wb.PivotCaches.Add(dataRange); //---THIS LINE HAS BEEN ADDED---

// First Pivot
XL.IXLWorksheet ptSheet1 = wb.Worksheets.Add("S2");
var pt1 = ptSheet1.PivotTables.AddNew("PivotTable1", ptSheet1.Cell(3, 1), cache);  
//Changed ptSheet.Cell... to ptSheet1.Cell...
pt1.ReportFilters.Add("CX");
pt1.RowLabels.Add("C1");
pt1.RowLabels.Add("C2");
pt1.RowLabels.Add("C3");
pt1.RowLabels.Add("C4");
pt1.ColumnLabels.Add("CL1");
pt1.ColumnLabels.Add("CL2");
pt1.ColumnLabels.Add("CL3");
pt1.Values.Add("V").SummaryFormula = XL.XLPivotSummary.Sum;

// Second Pivot
XL.IXLWorksheet ptSheet2 = wb.Worksheets.Add("S3");
var pt2 = ptSheet2.PivotTables.AddNew("PivotTable2", ptSheet2.Cell(3, 1), cache);  
//Changed ptSheet1.Cell... to ptSheet2.Cell...
pt2.ReportFilters.Add("QQ");
pt2.RowLabels.Add("C1");
pt2.RowLabels.Add("C2");
pt2.ColumnLabels.Add("CL1");
pt2.ColumnLabels.Add("CL2");
pt2.ColumnLabels.Add("CL3");
pt2.Values.Add("V").SummaryFormula = XL.XLPivotSummary.Sum;

Answer 2

The issue is caused by a ClosedXML implementation bug.

It can easily be reproduced by using the following snippet (a modified version of their Pivot Tables example) and opening the resulting file in Excel:

static void CreateTestPivotTables(string filePath)
{
    var wb = new XLWorkbook();

    var wsData = wb.Worksheets.Add("Data");            
    wsData.Cell("A1").Value = "Category";
    wsData.Cell("A2").Value = "A";
    wsData.Cell("A3").Value = "B";
    wsData.Cell("A4").Value = "B";
    wsData.Cell("B1").Value = "Number";
    wsData.Cell("B2").Value = 100;
    wsData.Cell("B3").Value = 150;
    wsData.Cell("B4").Value = 75;
    var source = wsData.Range("A1:B4");

    for (int i = 1; i <= 2; i++)
    {
        var name = "PT" + i;
        var wsPT = wb.Worksheets.Add(name);
        var pt = wsPT.PivotTables.AddNew(name, wsPT.Cell("A1"), source);
        pt.RowLabels.Add("Category");
        pt.Values.Add("Number")
            .ShowAsPctFrom("Category").And("A")
            .NumberFormat.Format = "0%";
    }

    wb.SaveAs(filePath);
}

The bug is located in XLWorkbook_Save.cs - GeneratePivotTables method:

private static void GeneratePivotTables(WorkbookPart workbookPart, WorksheetPart worksheetPart,
    XLWorksheet xlWorksheet,
    SaveContext context)
{
    foreach (var pt in xlWorksheet.PivotTables)
    {
        var ptCdp = context.RelIdGenerator.GetNext(RelType.Workbook);

        var pivotTableCacheDefinitionPart = workbookPart.AddNewPart<PivotTableCacheDefinitionPart>(ptCdp);
        GeneratePivotTableCacheDefinitionPartContent(pivotTableCacheDefinitionPart, pt);

        var pivotCaches = new PivotCaches();
        var pivotCache = new PivotCache {CacheId = 0U, Id = ptCdp};

        pivotCaches.AppendChild(pivotCache);

        workbookPart.Workbook.AppendChild(pivotCaches);

        var pivotTablePart =
            worksheetPart.AddNewPart<PivotTablePart>(context.RelIdGenerator.GetNext(RelType.Workbook));
        GeneratePivotTablePartContent(pivotTablePart, pt);

        pivotTablePart.AddPart(pivotTableCacheDefinitionPart, context.RelIdGenerator.GetNext(RelType.Workbook));
    }
}

by the line workbookPart.Workbook.AppendChild(pivotCaches); which adds multiple PivotCaches to workbookPart.Workbook while it's allowed to contain 0 or 1.

With that being said, the only way to fix it is inside the source code by modifying the above method as follows:

private static void GeneratePivotTables(WorkbookPart workbookPart, WorksheetPart worksheetPart,
    XLWorksheet xlWorksheet,
    SaveContext context)
{
    var pivotCaches = workbookPart.Workbook.GetFirstChild<PivotCaches>();
    foreach (var pt in xlWorksheet.PivotTables)
    {
        var ptCdp = context.RelIdGenerator.GetNext(RelType.Workbook);

        var pivotTableCacheDefinitionPart = workbookPart.AddNewPart<PivotTableCacheDefinitionPart>(ptCdp);
        GeneratePivotTableCacheDefinitionPartContent(pivotTableCacheDefinitionPart, pt);

        if (pivotCaches == null)
            workbookPart.Workbook.AppendChild(pivotCaches = new PivotCaches());
        var pivotCache = new PivotCache { CacheId = (uint)pivotCaches.Count(), Id = ptCdp };
        pivotCaches.AppendChild(pivotCache);

        var pivotTablePart =
            worksheetPart.AddNewPart<PivotTablePart>(context.RelIdGenerator.GetNext(RelType.Workbook));
        GeneratePivotTablePartContent(pivotTablePart, pt);
        pivotTablePart.PivotTableDefinition.CacheId = pivotCache.CacheId;

        pivotTablePart.AddPart(pivotTableCacheDefinitionPart, context.RelIdGenerator.GetNext(RelType.Workbook));
    }
}

Update: The good news are that my post triggered a ClosedXML source repository fix by Francois Botha (also credits to petelids who brought it up there), so you can take the code from there until their next release which hopefully will include it.