Question

All of a sudden this code has stopped outputting an Excel File. It was converting a DataTable, dtOutput, into an Excel file:

if (dtOutput.Rows.Count > 0)
{
    DataView dv = dtOutput.DefaultView;
    dv.Sort = "Outage Start Time";
    dtOutput = dv.ToTable();
    // Populates a column of the table
    dtOutput = addIncidentCounts(dtOutput);

    Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
    Workbook wb = xlApp.Workbooks.Add(XlWBATemplate.xlWBATWorksheet);
    Worksheet ws = (Worksheet)wb.Worksheets[1];
    ws.Name = "Retail Network Tracking Log";

    int col = 1;
    foreach (DataColumn column in dtOutput.Columns)
    {
        ws.Cells[1, col].Value2 = column.ColumnName;
        col++;
    }

    for (int i = 0; i < dtOutput.Rows.Count; i++)
    {
        for (int j = 0; j < dtOutput.Columns.Count; j++)
        {
            ws.Cells[i + 2, j + 1].Value2 = dtOutput.Rows[i][j];
        }
    }

    foreach (Range range in ws.UsedRange.Columns)
    {
        range.HorizontalAlignment = XlHAlign.xlHAlignLeft;
        range.Columns.AutoFit();
    }

    Range rangeE = ws.get_Range("E:E", Type.Missing);
    rangeE.NumberFormat = "d-mmm-yyyy hh:mm:ss";

    Range rangeF = ws.get_Range("F:F", Type.Missing);
    rangeF.NumberFormat = "d-mmm-yyyy hh:mm:ss";

    wb.Close(false, false, Type.Missing);
    xlApp.Quit();
    Marshal.ReleaseComObject(wb);
    Marshal.ReleaseComObject(xlApp);

    this.Close();
}

It has worked perfectly for weeks. I have made no changes to it. I have restarted VS, rebooted the computer, and finally reinstalled VS but I am still not getting any output. I have run it through the debugger as well and the code is definitely executing and attaining all of the proper values. I’m stumped.

Answer 1

Hans Passant was right. The call to close needed to be:

wb.Close(true, saveDirectory + "\\" + reportName, false);

Now the real mystery is how this code was working in the first place!