Excel文件无法保存

打开并修改Excel文件后，我试着保存它，使用:

excelApp.ActiveWorkbook.Save ();

但是数据似乎没有保存。

 private void ExportResultsToExcel()
 {
     string fullFilename = Regex.Match(Path, @".*''([^'']+$)").Groups[1].Value;
     string fileName = fullFilename.Substring(0, fullFilename.Length - 5);
     var templatePath = Path.Replace(fileName, "SolutionTemplate");
     var solutionPath = Path.Replace(fileName, fileName+"_Solution");
     System.IO.File.Copy(templatePath, solutionPath);
     var excelApp = new Excel.Application();
     var workbooks = excelApp.Workbooks;
     var workbook = workbooks.Open(solutionPath, 0, true, 5, "", "", true,
                                            XlPlatform.xlWindows, "'t", false,
                                            false, 0, true, 1, 0);
     var workSheets = workbook.Worksheets;
     var workSheet = (Worksheet) workSheets.Item[1];
     var rowIndex = 2;
     excelApp.DisplayAlerts = false;
     excelApp.ScreenUpdating = false;
     excelApp.Visible = false;
     excelApp.UserControl = false;
     excelApp.Interactive = false;
     foreach (var product in DemandData.Keys)
     {
         workSheet.Cells[rowIndex, 1] = product;
         workSheet.Cells[rowIndex, 2] = Result[product][0];
         workSheet.Cells[rowIndex, 3] = Result[product][1];
         workSheet.Cells[rowIndex, 4] = Result[product][2];
         workSheet.Cells[rowIndex, 5] = Result[product][3];
         workSheet.Cells[rowIndex, 6] = Result[product][4];
         workSheet.Cells[rowIndex, 7] = Result[product][5];
         workSheet.Cells[rowIndex, 8] = Result[product][6];
         workSheet.Cells[rowIndex, 9] = Result[product][7];
         workSheet.Cells[rowIndex, 10] = Result[product][8];
         workSheet.Cells[rowIndex, 11] = Result[product][9];
         workSheet.Cells[rowIndex, 12] = Result[product][10];
         workSheet.Cells[rowIndex, 13] = Result[product][11];
         workSheet.Cells[rowIndex, 14] = Result[product][12];
         rowIndex++;
     }
     int hWnd = excelApp.Application.Hwnd;
     //workbook.Save();
     excelApp.ActiveWorkbook.Save();
     Marshal.ReleaseComObject(workSheets);
     Marshal.ReleaseComObject(workSheet);
     Marshal.ReleaseComObject(workbooks);
     Marshal.ReleaseComObject(workbook);
     workbook.Close();
     excelApp.Quit();
     TryKillProcessByMainWindowHwnd(hWnd);
 }

var workbook = workbooks.Open(solutionPath, 0, true, 5, "", "", true,
                                            XlPlatform.xlWindows, "'t", false,
                                            false, 0, true, 1, 0);

var workbook = workbooks.Open(solutionPath, 0, false, 5, "", "", true,
                                            XlPlatform.xlWindows, "'t", false,
                                            false, 0, true, 1, 0);

 workbook.Close();
 Marshal.ReleaseComObject(workSheets);
 Marshal.ReleaseComObject(workSheet);
 Marshal.ReleaseComObject(workbooks);
 Marshal.ReleaseComObject(workbook);