Question

我使用Microsoft.Office.Interop.Excel将本地数据库表导出到excel文件。有五列。

如果行为400则需要大约20秒，

如果行是1200，则大约需要45秒，

如果行为5000则需要250-300秒。

有没有办法减少出口时间？或者这是最大的表现？如果您可以建议在速度方面改进我的代码或建议一些替代方案，我将不胜感激。由于它在后台工作，因此调用是必要的。我的代码是

       int rowCount = oLXTableDataGridView.RowCount;

        if (rowCount == 1)
        {
            MessageBox.Show("No data to export.");

            return;

        }

        this.Invoke((MethodInvoker)delegate
                {
                     this.ExportFilepictureBox.Image = Properties.Resources.Animation;
                     labelexpoertolx.Text = "Preparing to export...";
                });


                object misValue = System.Reflection.Missing.Value;


                conn = new SqlCeConnection(@"Data Source=|DataDirectory|\dontdelete.sdf");
                String selectgroup = "SELECT * FROM OLXTable";
                int namecol = 1;
                int cellcol = 2;
                int emailcol = 3;
                int citycol = 4;
                int categorycol = 5;


                    try
                    {

                        Excel.Application xlApp1;
                        Excel.Workbook xlWorkBook;
                        Excel.Worksheet xlWorkSheet;


                        xlApp1 = new Excel.Application();
                        xlWorkBook = xlApp1.Workbooks.Add(misValue);


                        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
                        // MessageBox.Show("this is file");


                        xlWorkSheet.Cells[1, namecol].Value2 = "Name";
                        xlWorkSheet.Cells[1, cellcol].Value2 = "Cell No";
                        xlWorkSheet.Cells[1, emailcol].Value2 = "Email";
                        xlWorkSheet.Cells[1, citycol].Value2 = "City";
                        xlWorkSheet.Cells[1, categorycol].Value2 = "Category";

                        SqlCeDataReader reader = null;


                        //conn = new SqlCeConnection(selectnumbers);
                        conn.Open(); //open the connection
                        SqlCeCommand selecectnumberscmd = new SqlCeCommand(selectgroup, conn);
                        reader = selecectnumberscmd.ExecuteReader();
                        int i =  1;

                        while (reader.Read())
                        {
                            xlWorkSheet.Cells[i, namecol].Value2 = reader.GetString(1);
                            xlWorkSheet.Cells[i, cellcol].Value2 = reader.GetInt64(2);
                            xlWorkSheet.Cells[i, emailcol].Value2 = reader.GetString(3); ;
                            xlWorkSheet.Cells[i, citycol].Value2 = reader.GetString(4);
                            xlWorkSheet.Cells[i, categorycol].Value2 = reader.GetString(5);
                            i++;

                        }
                        conn.Close();
                        xlWorkBook.Close(true, misValue, misValue);
                        xlApp1.Quit();
                        releaseObject(xlWorkSheet);
                        releaseObject(xlWorkBook);
                        releaseObject(xlApp1);



                        this.Invoke((MethodInvoker)delegate
                        {
                            this.ExportFilepictureBox.Image = null;
                            labelexpoertolx.Text = "";
                        });


                    }
                    catch (Exception e13)
                    {
                        MessageBox.Show("Error Exporting data" + e13.Message);
                        conn.Close();


                    }
                    Cursor.Current = Cursors.Default;

和

private void releaseObject(object obj)
    {
        try
        {
            System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
            obj = null;
        }
        catch (Exception ex)
        {
            obj = null;
            MessageBox.Show("Exception Occured while releasing object " + ex.ToString());
        }
        finally
        {
            GC.Collect();
        }
    }

Answer 1

如果你已经开始使用互操作，那么最好首先创建一个值数组然后一次性写出来而不是循环遍历行 - 互操作在这方面是非常慢的

就个人而言，我建议抛弃互操作并使用开放式xml库（例如EPPlus）来完成此类任务。我发现它更容易使用，通常更高效。作为奖励，它摆脱了所有令人厌烦的凌乱释放com对象编组的东西; - ）

这将替换try块中的所有内容，如下所示：

using (ExcelPackage package = new ExcelPackage())
{
    ExcelWorksheet ws = package.Workbook.Worksheets.Add("Data");
    ws.Cells[1, namecol].Value = "Name";
    ws.Cells[1, cellcol].Value = "Cell No";
    ws.Cells[1, emailcol].Value = "Email";
    ws.Cells[1, citycol].Value = "City";
    ws.Cells[1, categorycol].Value = "Category";

    SqlCeDataReader reader = null;

    conn.Open(); //open the connection
    SqlCeCommand selecectnumberscmd = new SqlCeCommand(selectgroup, conn);
    reader = selecectnumberscmd.ExecuteReader();
    int i = 1;

    while (reader.Read())
    {
        ws.Cells[i, namecol].Value = reader.GetString(1);
        ws.Cells[i, cellcol].Value = reader.GetInt64(2);
        ws.Cells[i, emailcol].Value = reader.GetString(3); ;
        ws.Cells[i, citycol].Value = reader.GetString(4);
        ws.Cells[i, categorycol].Value = reader.GetString(5);
        i++;

    }

    conn.Close();

    //Now you have options to export the file - just save someplace, get a byte array or get a reference to the output stream etc with some of the following:

    package.SaveAs(someFilePathString);
    someByteArrayVariable =  package.GetAsByteArray();
    package.Stream;
}

Answer 2

作为替代方案，您可以使用SwiftExcel库（免责声明：我写了该库），就像EPPlus一样，它不使用互操作，但由于将数据直接流到文件中而具有更好的性能，该速度更快并且没有任何内存都会影响大批量。

以下是Nuget命令，可将其添加到您的项目中：

PM> Install-Package SwiftExcel

这是使用方法：

using (var ew = new ExcelWriter("C:\\temp\\test.xlsx"))
{
    for (var row = 1; row <= 100; row++)
    {
        for (var col = 1; col <= 10; col++)
        {
            ew.Write($"row:{row}-col:{col}", col, row);
        }
    }
}

使用Microsoft.Office.Interop.Excel将速度性能导出到excel文件

2 个答案: