將SQL db導出到Excel問題

Question

我正在嘗試設置一個按鈕，以便輕松地將我的應用程序中的數據庫導出到Excel工作表。 但是我遇到了讓它運轉的問題。 我無法弄清楚出了什么問題，因為我沒有看到任何錯誤。

 {
            string cs = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf";
            SqlConnection con = new SqlConnection(cs);
            con.Open();
            SqlCommand command = new SqlCommand("SELECT * FROM AvSites", con);
            SqlDataAdapter dataadpter = new SqlDataAdapter(command);
            DataTable datatable = new DataTable("AvSites");
            dataadpter.Fill(datatable);
            datatable.WriteXml(Application.StartupPath + "AvSitesDbExport.xlsx");
            MessageBox.Show("export data");

        }

當我在調試模式下運行應用程序時，該按鈕在我的桌面上創建一個xml（xlsx）文件，我想這沒關系？ 因為它處於調試模式，所以不確定這里適用的規則。

但是，如果我發布應用程序，我不會看到文件在任何地方創建。

難道我做錯了什么 ？ Application.StartupPath應該返回執行.exe的目錄，對嗎？

Answer 1

 {
            string cs = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf";
            SqlConnection con = new SqlConnection(cs);
            con.Open();
            SqlCommand command = new SqlCommand("SELECT * FROM AvSites", con);
            SqlDataAdapter dataadpter = new SqlDataAdapter(command);
            DataTable datatable = new DataTable("AvSites");
            WriteExcelWithNPOI(datatable,"xls")  /* "xls" or "xlsx"
            MessageBox.Show("export data");

        }
public void WriteExcelWithNPOI(DataTable dt, String extension)
      {           
          IWorkbook workbook;          

          if (extension == "xlsx") {
              workbook = new XSSFWorkbook();                
          }
          else if (extension == "xls")
          {
              workbook = new HSSFWorkbook();
          }
          else {
              throw new Exception("This format is not supported");
          }

          ISheet sheet1 = workbook.CreateSheet("Sheet 1");

          //make a header row
          IRow row1 = sheet1.CreateRow(0);

          for (int j = 0; j < dt.Columns.Count; j++)
          {

              ICell cell = row1.CreateCell(j);
              String columnName = dt.Columns[j].ToString();
              cell.SetCellValue(columnName);
          }

          //loops through data
          for (int i = 0; i < dt.Rows.Count; i++)
          {
              IRow row = sheet1.CreateRow(i + 1);
              for (int j = 0; j < dt.Columns.Count; j++)
              {

                  ICell cell = row.CreateCell(j);
                  String columnName = dt.Columns[j].ToString();
                  cell.SetCellValue(dt.Rows[i][columnName].ToString());
              }
          }

          using (var exportData = new MemoryStream())
          { 
              Response.Clear();                
              workbook.Write(exportData);
              if (extension == "xlsx") //xlsx file format
              {
                  Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                  Response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}", "ContactNPOI.xlsx"));                   
                  Response.BinaryWrite(exportData.ToArray());             
              }
              else if (extension == "xls")  //xls file format
              { 
                  Response.ContentType = "application/vnd.ms-excel";
                  Response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}", "ContactNPOI.xls"));
                  Response.BinaryWrite(exportData.GetBuffer());
              }   
              Response.End();
          }
      }