c# - c# wpf中将数据导出到文件时如何显示进度条

Question

**我已经完成了将数据从数据库导出到文件的部分，但是我发现有时等待这个动作完成需要很长时间。所以我想在我的程序中添加一个进度条，但这是我的问题：

1. 我不知道 xx.xls 文件有多大

2. 我不知道如何获取已导出文件大小的阶段

所以我不知道如何计算进度条的百分比。我应该怎么做才能获得我需要的所有信息，或者还有其他解决方案吗？非常感谢这是我的导出数据代码：**

SaveFileDialog savefiledialog = new SaveFileDialog();
                savefiledialog.FileName = @"data.xlsx";

                if (!(bool)savefiledialog.ShowDialog())
                    return;



                DbHelper dh = new DbHelper("data.mdb");
                ApplicationClass excel = new ApplicationClass();


                Workbooks workbooks = excel.Workbooks;
                Workbook workbook = workbooks.Add();


                Worksheet sheet1 = (Worksheet)excel.ActiveSheet;

                ArrayList itemList = dh.setTable("Item").where("1=1").select();
                sheet1.Cells[1, "A"] = "col1";
                sheet1.Cells[1, "B"] = "col2";
                sheet1.Cells[1, "C"] = "col3";



                int i = 2;
                foreach (Item item in itemList)
                {
                    sheet1.Cells[i, "A"] = item.Website;
                    sheet1.Cells[i, "B"] = item.Shop_id;
                    sheet1.Cells[i, "C"] = item.Title;
                    i++;
                }


                sheet1.Range["A1"].AutoFormat(Microsoft.Office.Interop.Excel.XlRangeAutoFormat.xlRangeAutoFormatClassic1);


                string fileName = string.Format(savefiledialog.FileName, Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory));

                // Save this data as a file
                System.Action<string, string, string, string, string, string, string, string, string, string> action = sheet1.SaveAs;
                BackgroundWorker b = new BackgroundWorker();
                sheet1.SaveAs(fileName);

                GC.Collect();
                GC.WaitForPendingFinalizers();

                Marshal.FinalReleaseComObject(sheet1);

                workbook.Close(Type.Missing, Type.Missing, Type.Missing);
                Marshal.FinalReleaseComObject(workbooks);

                excel.Quit();

Answer 1

您可以使用表格行数，或者只显示一个不确定的状态，说这需要几分钟。你试过批量复制吗？这将使您的出口更快。