Setting Column.Collapsed to true or false don't work

[lingtianmail-oss]

EPPlus usage

Noncommercial use

Environment

Windows 11

Epplus version

8.1.0

Spreadsheet application

Excel

Description

Setting Column.Collapsed to true or false don't work

sample.xlsm

`using OfficeOpenXml;

using System.IO;

using Excel = Microsoft.Office.Interop.Excel;

class TestEpplus
{

    static void Main()
    {
        string sourceFile = @"d:\sample.xlsm";


   

    EPPlusLicense ePPlusLicense = ExcelPackage.License;
    ePPlusLicense.SetNonCommercialOrganization("TEST");

    using (var package = new ExcelPackage(new FileInfo(sourceFile)))
    {
        foreach (ExcelWorksheet worksheet in package.Workbook.Worksheets)
        {
            for (int i = 3; i <= 9; i++)
            {

                worksheet.Column(i).Collapsed = false;
            }

        }

        package.Save();
    }
    Excel.Application excelApp = null;
    Excel.Workbook workbook = null;
    excelApp = new Excel.Application();
    excelApp.Visible = true;

    workbook = excelApp.Workbooks.Open(sourceFile);

}

}

`

[lingtianmail-oss]

I set the Collapsed property of the outline columns to false, but when I open Excel, the grouped columns are still collapsed.

[AdrianEPPlus]

Hello.

You can use worksheet.Columns[i].ExpandChildren(true); instead.