Question

我是C＃和wpf的新手，但我试图从+100 xlsx文件中读取大量数据（abt.40000 x 34 cell）并将它们连接成一个文本文件。

我已经制作了一个小型的C＃（wpf）应用程序来做到这一点。我看到一些随机的内存泄漏，有时当我运行它时，一切顺利，它需要的内存（根据Windows任务管理器）保持在1 GB以下，而其他时候它吃，几乎所有我的8 GB。

使用System.IO.File.ReadAllLines(pathtotextfilewithxlsxfilenames)时发现了一种情况而使用谨慎的例子（在代码中指定文件名）不会以同样的方式导致问题。（我已经将带有xlsx-filenames的文本文件中的相同名称复制并粘贴到代码中（用", "替换了标签）所以它应该是相同的...据我所知。）

该应用大致如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Data;
using System.IO;
using System.Data.OleDb;

namespace WpfApps
{
  /// <summary>
  /// Interaction logic for MainWindow.xaml
  /// </summary>
  public partial class MainWindow : Window
  {
  string s_path_to_list_of_xlsx_files;
  public MainWindow()
  {
    InitializeComponent();
  }

  private void Button_Click(object sender, RoutedEventArgs e)
  {
    string path = @"F:\...\xls_files\";
    string[] fnlist = { "datafile1.xlsx", "datafile2.xlsx", ... "datafileN.xlsx" };

    //string[] fnlist = System.IO.File.ReadAllLines(@"f:\...\xlsfiles.txt"); // It seems as if using this line, compared to the discreet line above causes memory leak.
    DataTable measurementdata = new DataTable();
    measurementdata.Columns.Add("C1", typeof(double));
    measurementdata.Columns.Add("C2", typeof(double));
    ...
    measurementdata.Columns.Add("C34", typeof(double));

    using (StreamWriter sw = File.CreateText(path + "allresult.txt"))
    {
      bool firstCol = true;
      foreach (DataColumn col in measurementdata.Columns)
      {
        if (!firstCol) sw.Write(", ");
        sw.Write(col.ColumnName);
        firstCol = false;
      }
      sw.WriteLine();
    }
    foreach (var fn in fnlist)
    {
        DataTable filedt = GetDataTableFromExcel(path + fn, false);
        using (StreamWriter sw = File.AppendText(path + "allresult.txt"))
        {
          foreach (DataRow row in filedt.Rows)
          {
              bool firstCol = true;
              foreach (DataColumn col in filedt.Columns)
              {
                if (!firstCol) sw.Write(", ");
                sw.Write(row[col].ToString());
                firstCol = false;
              }
              sw.WriteLine();
          }
        }
    }
  }

  public static DataTable GetDataTableFromExcel(string path, bool hasHeader = true)
  {
    using (var pck = new OfficeOpenXml.ExcelPackage())
    {
        using (var stream = File.OpenRead(path))
        {
          pck.Load(stream);
        }
        var ws = pck.Workbook.Worksheets["Logged Data"];
        int startrow = 72;
        int endrow = 43271;
        DataTable tbl = new DataTable();
        foreach (var firstrowcell in ws.Cells[startrow - 1, 8, startrow - 1, 41])
        {
              tbl.Columns.Add(firstrowcell.Text);
        }
        for (int rowNum = startrow; rowNum <= endrow; rowNum++)
        {
          var wsRow = ws.Cells[rowNum, 8, rowNum, 41];
          DataRow row = tbl.Rows.Add();
          foreach (var cell in wsRow)
          {
              var cellvalue = cell.Value;
              if (cellvalue == null) cellvalue = "0";
              row[cell.Start.Column - 8] = cellvalue;
          }
        }
        return tbl;
    }
  }

有人能看到明显的问题吗？

使用C＃读取xlsx文件时出现随机内存泄漏

0 个答案: