Writing to excel worksheet from custom object

Question

I have a client application (excel addIn) that retrievs data from WCF server.

These are the classes :

    public class myWorksheet
    {
      public int Id { get; set; }
      public string WorksheetName { get; set; }
      public List<myData> MyDataChildren { get; set; }
      public List<string> Dependencies { get; set; }
    }

    public class myData
    {
      public int Id { get; set; }
      public int WorksheetId { get; set; }
      public int RowId { get; set; }
      public string ColumnId { get; set; }
      public string Value { get; set; }
      public string Formula { get; set; }
      public string Comment { get; set; }
    }

Dependencies - list of worksheet names that the current worksheet has a reference to (in formulas)

I retrieve the List from WCF (actually IEnumerable) and have that data on the client. The problem is that when I'm writing the data to excel it takes way to long.

What I'm doing is :

1. Create empty worksheets in workbook
2. Activate one worksheet (the one user is currenty looking at)

3. On "Application_SheetActivate" event

   • First load all data into worksheets that are in the Dependencies
   • Load data into the sheet user is looking at

Like this :

    public List<myWorksheet> WorksheetList { get; set; }

    private void Rebind(myWorksheet currWorksheet, out Excel.Workbook workbook)
    {

      foreach (string connectedWorksheet in currWorksheet.Dependencies)
      {
        myWorksheet ws = DataHelper.FindWorksheetFromList(connectedWorksheet, this.WorksheetList);
        Excel.Worksheet sheet = DataHelper.FindWorksheetFromWorkbook(connectedWorksheet,workbook);

        this.LoadData(sheet,ws);
      }


        Excel.Worksheet sheetMain = DataHelper.FindWorksheetFromWorkbook(currWorksheet.WorksheetName,workbook);
        this.LoadData(sheetMain,currWorksheet);
    }

    private void LoadData(Excel.Worksheet worksheet, myWorksheet worksheetEnt)
    {
        foreach (myData cell in worksheetEnt.MyDataChildren)
        {
            Excel.Range excelCell = worksheet.Range(cell.ColumnId.ToString() + cell.RowId.ToString());
            excelCell.Value2 = cell.Value;
            excelCell.Formula = cell.Formula;
            excelCell.AddComment(cell.Comment);
        }
    }

The problem is :

• There are around 400 worksheets in List
• Each worksheet has around 2000 cells (myData).

• Some worksheets have about 200 dependencies. (and loading of that dependencies takes 15 minutes).

• Is this iteration what I'm doing wrong? Is there a better/ faster way that I'm not aware of?

Answer 1

Managed to solve the issue.

Tried

• wiring in the data using arrays
• setting Application.ScreenUpdating to False

And that helped a little. But what really did the trick is

• Application.Calculation = Excel.XlCalculation.xlCalculationManual

so my code now looks like this:

private void Rebind(myWorksheet currWorksheet, out Excel.Workbook workbook)
{

  currWorksheet.Application.Calculation = Excel.XlCalculation.xlCalculationManual
  currWorksheet.Application.ScreenUpdating=False

  foreach (string connectedWorksheet in currWorksheet.Dependencies)
  {
    myWorksheet ws = DataHelper.FindWorksheetFromList(connectedWorksheet, this.WorksheetList);
    Excel.Worksheet sheet = DataHelper.FindWorksheetFromWorkbook(connectedWorksheet,workbook);

    this.LoadData(sheet,ws);
  }

  Excel.Worksheet sheetMain = DataHelper.FindWorksheetFromWorkbook(currWorksheet.WorksheetName,workbook);
  this.LoadData(sheetMain,currWorksheet);

  currWorksheet.Application.Calculation = Excel.XlCalculation.xlCalculationAutomatic
  currWorksheet.Application.ScreenUpdating=True
 }