Creating Multiple work sheet from multiple thread throwing error root level is invalid

Question

I am using EPPlus to generate excel file with multiple sheets.I am trying to add multiple worksheet to a single excel file from different thread and getting ambiguous error message root level is invalid

Here is my code. please some one have look and tell me what i am doing wrong in my code ?

ExcelPackage excelPackage = null;  
private void button1_Click(object sender, EventArgs e)  
{  
    string exclpath = @"d:\Test1.xlsx";  
  
    FileInfo fi = new FileInfo(@exclpath);  
    excelPackage = new ExcelPackage(fi);  
  
    Action[] actions;  
  
    actions = new Action[]  
    {  
        () => Test1(),  
        () => Test2()  
    };  
  
    Parallel.Invoke(actions);  
    excelPackage.Save();  
}  
  
private void Test1()  
{  
    OfficeOpenXml.ExcelWorksheet ws = excelPackage.Workbook.Worksheets.Add("Delta");  
    ws.Cells[1, 1].Value = "Test Delta";  
}  
  
private void Test2()  
{  
    OfficeOpenXml.ExcelWorksheet ws = excelPackage.Workbook.Worksheets.Add("Horizontal");  
    ws.Cells[1, 1].Value = "Test Horizontal";  
}  

Please guide me how can i add multiple sheets with data from different thread into single excel file. is it not possible ?

if possible please guide me. Thanks

Answer 1

According to their documentation, you need to add LicenseContext to the code.

 ExcelPackage.LicenseContext = OfficeOpenXml.LicenseContext.Commercial;  
 ExcelPackage.LicenseContext = OfficeOpenXml.LicenseContext.NonCommercial;  

When I test this code, if I call Test1 or Test2 alone, there will be no problems with the code, but when I call both at the same time, the generated excel file will look like this:

This seems to be a problem caused by this package. I suggest you go to the github repository they provide to ask questions about this package.

In addition, do you consider other packages, such as OpenXML, I used this package to write a similar code:

       static SpreadsheetDocument spreadsheetDocument;  
        static Sheets sheets;  
        static WorksheetPart worksheetPart;  
        public static void M1()  
        {  
            string filePath = @"d:\test\excel\output.xlsx";  
            spreadsheetDocument = SpreadsheetDocument.Create(filePath, SpreadsheetDocumentType.Workbook);  
  
            WorkbookPart workbookpart = spreadsheetDocument.AddWorkbookPart();  
            workbookpart.Workbook = new Workbook();  
            sheets = spreadsheetDocument.WorkbookPart.Workbook.AppendChild<Sheets>(new Sheets());  
            worksheetPart = workbookpart.AddNewPart<WorksheetPart>();  
            worksheetPart.Worksheet = new Worksheet(new SheetData());  
  
            Action[] actions;  
  
            actions = new Action[]  
            {  
                 () => WorkM1(),  
                 () => WorkM2()  
            };  
  
            Parallel.Invoke(actions);  
  
            workbookpart.Workbook.Save();  
            spreadsheetDocument.Close();  
        }  
        public static void WorkM1()   
        {  
            Sheet sheet = new Sheet()  
            {  
                Id = spreadsheetDocument.WorkbookPart.GetIdOfPart(worksheetPart),  
                SheetId = 2,  
                Name = new StringValue("Sheet1")  
            };  
            sheets.Append(sheet);  
        }  
        public static void WorkM2()  
        {  
            Sheet sheet = new Sheet()  
            {  
                Id = spreadsheetDocument.WorkbookPart.GetIdOfPart(worksheetPart),  
                SheetId = 3,  
                Name = new StringValue("Sheet2")  
            };  
            sheets.Append(sheet);  
        }  

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