使用EPPlus使用图表重命名工作表

Question

I've got an EPPlus application that is using an existing Excel worksheet as a template for an indeterminate number of new sheets (the size of the data set will vary).

I'm trying to accomplish this by either creating the new sheets, like this:

    ExcelWorksheet templateWs = templateFile.Workbook.Worksheets["Sheet1"];
    ws = ExcelFile.Workbook.Worksheets.Add(string.Format("{0} {1}", "Sample ", sampleID), templateWs);

or else

    ExcelWorksheet templateWs = templateFile.Workbook.Worksheets["Sheet1"];
    ws = ExcelFile.Workbook.Worksheets.Add("Sheet1", templateWs);
    ws.Name = string.Format("{0} {1}", "Sample ", sampleID);

Unfortunately, both of these have the same result: the worksheet name changes, but the data series reference in the charts does not. It continues to reference "Sheet1".

Is there a way around this? Possibly some way to define the data series reference in the chart to refer to "current sheet" instead of "Sheet1"? Or some EPPlus trick to change the sheet reference in a chart?

Thanks

Answer 1

The template-based Add overload does not handle charts very well. I havent ever seen a good solution other than manually fixing them after. Not pretty since there are some many edge cases with charts which is probably why it is not as well developed as it needs to be.

As an example, if we use the chart generated here:

How to put two series with different types of charts inside a control chart using Epplus?

we have a case of an ExcelChart WITHIN an ExcelChart . Really sneaky! So to do a proper copy you have to loop through both the charts PlotArea and ExcelSeries . So, using the excel file generated by that test method in my answer we get something like this:

[TestMethod]
public void Chart_Template_Rename_Test()
{
    //https://stackoverflow.com/questions/57829441/renaming-sheet-with-a-chart-using-epplus

    var templateFileInfo = new FileInfo(@"C:\temp\Chart_Two_Series.xlsx");
    Assert.IsTrue(templateFileInfo.Exists);

    var fileInfo = new FileInfo(@"C:\temp\Chart_Template_Rename_Test.xlsx");
    if (fileInfo.Exists)
        fileInfo.Delete();

    using (var templateFile = new ExcelPackage(templateFileInfo))
    using (var ExcelFile = new ExcelPackage(fileInfo))
    {
        ExcelWorksheet ws;
        var sampleID = "Sample1";
        var origWsName = "Content";

        ExcelWorksheet templateWs = templateFile.Workbook.Worksheets[origWsName];
        ws = ExcelFile.Workbook.Worksheets.Add(origWsName, templateWs);
        ws.Name = string.Format("{0} {1}", "Sample ", sampleID);

        //Look for "top-level" charts
        foreach (var excelDrawing in ws.Drawings)
        {
            if (!(excelDrawing is ExcelChart chart))
                continue;

            //Charts can contain other charts so use plot area to loop through them
            foreach (var chartType in chart.PlotArea.ChartTypes)
            foreach (ExcelChartSerie serie in chartType.Series)
            {
                serie.Series = serie.Series.Replace(origWsName, ws.Name);
                serie.XSeries = serie.XSeries.Replace(origWsName, ws.Name);

                if (serie.HeaderAddress != null)
                    serie.HeaderAddress = new ExcelAddressBase(serie
                        .HeaderAddress
                        .Address
                        .Replace(origWsName, ws.Name)
                    );
            }
        }

        ExcelFile.Save();
    }
}

Which gives this in the new Workbook Worksheet (note the Sheet name which was originally "Content"):

However, keep in mind that if a the original XLXS has been opened and by Excel itself that can create other problems with coping sheets with charts. Again, edge cases that have to be dealt with.