在 ASP.Net C# 中将大数据导出到 excel

Question

我正在尝试将一个数据集导出到 Excel 文件。数据集包含 20 多个数据表（每个表将在最终输出的 excel 文件中显示为单独的表），每个表包含超过 30+k 行，大约 10 列。我正在从其他资源中读取这些数据并将其保存到数据集中。不使用任何数据库来存储它。我正在使用来自here 的 Open XML 和 Closed XML 来执行此过程。它对 15-20 个数据表的工作正常，但超过 25 个它需要太多时间。对此的任何建议或帮助将不胜感激。

示例代码：

 using (XLWorkbook wb = new XLWorkbook())
 {
   foreach (DataTable dt in dsData.Tables)
   {
     wb.Worksheets.Add(dt);
   }
   Response.Clear();
   Response.Buffer = true;
   Response.Charset = "";
   Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
   Response.AddHeader("content-disposition", "attachment;filename=DataSet.xlsx");
   wb.SaveAs(Response.OutputStream);
   Response.Flush();
   Response.End();   
 }

Answer 1

经过一些研究，我想出了一个解决方案，我用 100 万 + 数据测试了下面的代码，并且运行良好。可能对其他人有帮助。 我删除了 closedxml 参考，并添加了“Interop.Microsoft.Office.Core.dll”参考。然后我写了以下代码。

必需的命名空间： 使用 Excel = Microsoft.Office.Interop.Excel， 使用 System.Runtime.InteropServices

    Excel.Workbook xlWorkBook;
    Excel.Application xlApp;
    Excel.Worksheet xlWorkSheet;
    Excel.Range Startrange;
    Excel.Range HeaderStartrange;
    public bool StartExport(DataTable dtbl, bool isFirst, bool isLast, string strOutputPath, string TemplateLocation, string TemplateFullName, int SectionOrder, int totalNoOfSheets)
    {
        bool isSuccess = false;
        try
        {
            if (isFirst)
            {
                CopyTemplate(TemplateLocation, strOutputPath, TemplateFullName);
                xlApp = new Excel.Application();
                if (xlApp == null)
                {
                    throw new Exception("Excel is not properly installed!!");
                }
                xlWorkBook = xlApp.Workbooks.Open(@strOutputPath + TemplateFullName, 0, false, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);

                // To Add Sheets Dynamically
                for (int i = 0; i <= totalNoOfSheets; i++)
                {
                    int count = xlWorkBook.Worksheets.Count;
                    Excel.Worksheet addedSheet = xlWorkBook.Worksheets.Add(Type.Missing,
                            xlWorkBook.Worksheets[count], Type.Missing, Type.Missing);
                    addedSheet.Name = "Sheet " + i.ToString();
                }
            }
            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(SectionOrder);
            Startrange = xlWorkSheet.get_Range("A2");
            HeaderStartrange = xlWorkSheet.get_Range("A1");
            FillInExcel(Startrange, HeaderStartrange, dtbl);
            xlWorkSheet.Name = dtbl.TableName;
            if (isLast)
            {
                xlApp.DisplayAlerts = false;
                xlWorkBook.SaveAs(@strOutputPath + TemplateFullName, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Excel.XlSaveAsAccessMode.xlNoChange, Type.Missing, Type.Missing, Type.Missing,
                    Type.Missing, Type.Missing);
                xlWorkBook.Close(true, null, null);
                xlApp.Quit();
                Marshal.ReleaseComObject(xlWorkSheet);
                Marshal.ReleaseComObject(xlWorkBook);
                Marshal.ReleaseComObject(xlApp);
                GC.WaitForPendingFinalizers();
                GC.Collect();
                isSuccess = true;
            }
        }
        catch (Exception ex)
        {
            isSuccess = false;
            throw;
        }
        return isSuccess;
    }

    private void FillInExcel(Excel.Range startrange, Excel.Range HeaderStartRange, DataTable dtblData)
    {
        int rw = 0;
        int cl = 0;
        try
        {
            // Fill The Report Content Data Here
            rw = dtblData.Rows.Count;
            cl = dtblData.Columns.Count;
            string[,] data = new string[rw, cl];
            // Adding Columns Here
            for (var row = 1; row <= rw; row++)
            {
                for (var column = 1; column <= cl; column++)
                {
                    data[row - 1, column - 1] = dtblData.Rows[row - 1][column - 1].ToString();
                }
            }
            Excel.Range endRange = (Excel.Range)xlWorkSheet.Cells[rw + (startrange.Cells.Row - 1), cl + (startrange.Cells.Column - 1)];
            Excel.Range writeRange = xlWorkSheet.Range[startrange, endRange];
            writeRange.Value2 = data;
            writeRange.Formula = writeRange.Formula;
            data = null;
            startrange = null;
            endRange = null;
            writeRange = null;
        }

        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

我在上面为每个循环调用了这个 startExport 函数，其中包含所需的参数，例如（数据、第一个或最后一个工作表、输出路径、模板名称、部分顺序和所需的工作表总数）