How to group rows/columns in EPPlus

Question

Is there a way to achieve this in EPPlus? Only thing I could find on the internet is grouping specific data for example:

AAA     --->    AAA     5 occurrences
AAA             BBB     2 occurences
BBB
BBB    
AAA
AAA
AAA

but not visually like in the screenshots

Solution

Looks like you want to do Row and Columns outlines that are collapsed. This should demonstrate how to do that:

[TestMethod]
public void Row_Col_Grouping_Test()
{
    //http://stackoverflow.com/questions/32760210/how-to-group-rows-columns-in-epplus

    //Throw in some data
    var datatable = new DataTable("tblData");
    datatable.Columns.AddRange(new[]
    {
        new DataColumn("Header", typeof (string)), new DataColumn("Col1", typeof (int)), new DataColumn("Col2", typeof (int)), new DataColumn("Col3", typeof (object))
    });

    for (var i = 0; i < 10; i++)
    {
        var row = datatable.NewRow();
        row[0] = String.Format("Header {0}", i); row[1] = i; row[2] = i*10; row[3] = Path.GetRandomFileName(); datatable.Rows.Add(row);
    }

    //Create a test file
    var fi = new FileInfo(@"c:\temp\grouping.xlsx");
    if (fi.Exists)
        fi.Delete();

    using (var pck = new ExcelPackage(fi))
    {
        var worksheet = pck.Workbook.Worksheets.Add("Sheet1");
        worksheet.Cells.LoadFromDataTable(datatable, true);

        worksheet.Cells["B12"].Formula = "SUM(B2:B11)";
        worksheet.Cells["C12"].Formula = "SUM(C2:C11)";

        //Row Group 1
        for (var i = 2; i <= 6; i++)
        {
            worksheet.Row(i).OutlineLevel = 1;
            worksheet.Row(i).Collapsed = true;
        }

        //Row Group 2
        for (var i = 6; i <= 10; i++)
        {
            worksheet.Row(i).OutlineLevel = 2;
            worksheet.Row(i).Collapsed = true;
        }

        //Column Group
        for (var i = 2; i <= 4; i++)
        {
            worksheet.Column(i).OutlineLevel = 1;
            worksheet.Column(i).Collapsed = true;
        }

        pck.Save();
    }
}