我的好奇心问题比什么都重要。我正在开发一个从listview导出到csv的wpf应用程序。我写的代码（有效）如下：
private void Launch(object sender, RoutedEventArgs e)
{
Microsoft.Office.Interop.Excel.Application oExcel = new Microsoft.Office.Interop.Excel.Application();
oExcel.Visible = true;
Microsoft.Office.Interop.Excel.Workbook oWorkBook = oExcel.Workbooks.Add(Microsoft.Office.Interop.Excel.XlSheetType.xlWorksheet);
Microsoft.Office.Interop.Excel.Worksheet oSheet = (Microsoft.Office.Interop.Excel.Worksheet)oExcel.ActiveSheet;
int row = 2; //allow for header row
int column = 1;
oSheet.Cells[1, 1] = "Name";
oSheet.Cells[1, 2] = "CPU";
oSheet.Cells[1, 3] = "RAM";
oSheet.Cells[1, 4] = "IP Address";
oSheet.Cells[1, 5] = "Subnet Mask";
oSheet.Cells[1, 6] = "Port Group";
oSheet.Cells[1, 7] = "Default Gateway";
oSheet.Cells[1, 8] = "DNS";
oSheet.Cells[1, 9] = "Description";
oSheet.Cells[1, 10] = "Template";
oSheet.Cells[1, 11] = "Host";
oSheet.Cells[1, 12] = "Site";
oSheet.Cells[1, 13] = "Folder";
oSheet.Cells[1, 14] = "DataStore";
oSheet.Cells[1, 15] = "Patch Method";
oSheet.Cells[1, 16] = "HDD1Size";
oSheet.Cells[1, 17] = "HDD1Format";
oSheet.Cells[1, 18] = "HDD2Size";
oSheet.Cells[1, 19] = "HDD2Format";
oSheet.Cells[1, 20] = "HDD3Size";
oSheet.Cells[1, 21] = "HDD3Format";
oSheet.Cells[1, 22] = "HDD4Size";
oSheet.Cells[1, 23] = "HDD4Format";
oSheet.Cells[1, 24] = "HDD5Size";
oSheet.Cells[1, 25] = "HDD5Format";
foreach (var oVM in MyItems)
{
oSheet.Cells[row, column] = oVM.Name;
oSheet.Cells[row, (column + 1)] = oVM.CPU;
oSheet.Cells[row, (column + 2)] = oVM.RAM;
oSheet.Cells[row, (column + 3)] = oVM.IP;
oSheet.Cells[row, (column + 4)] = oVM.Subnet;
oSheet.Cells[row, (column + 5)] = oVM.PortGroup;
oSheet.Cells[row, (column + 6)] = oVM.Gateway;
oSheet.Cells[row, (column + 7)] = oVM.DNS;
oSheet.Cells[row, (column + 8)] = oVM.Description;
oSheet.Cells[row, (column + 9)] = oVM.Template;
oSheet.Cells[row, (column + 10)] = oVM.Host;
oSheet.Cells[row, (column + 11)] = oVM.Site;
oSheet.Cells[row, (column + 12)] = oVM.Folder;
oSheet.Cells[row, (column + 13)] = oVM.Datastore;
oSheet.Cells[row, (column + 14)] = oVM.Patch;
oSheet.Cells[row, (column + 15)] = oVM.HDD1Size;
oSheet.Cells[row, (column + 16)] = oVM.HDD1Format;
oSheet.Cells[row, (column + 17)] = oVM.HDD2Size;
oSheet.Cells[row, (column + 18)] = oVM.HDD2Format;
oSheet.Cells[row, (column + 19)] = oVM.HDD3Size;
oSheet.Cells[row, (column + 20)] = oVM.HDD3Format;
oSheet.Cells[row, (column + 21)] = oVM.HDD4Size;
oSheet.Cells[row, (column + 22)] = oVM.HDD4Format;
oSheet.Cells[row, (column + 23)] = oVM.HDD5Size;
oSheet.Cells[row, (column + 24)] = oVM.HDD5Format;
row++;
}
oExcel.Application.ActiveWorkbook.SaveAs(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory) + "\\example", 6);
}
如上所述，这有效，但速度很慢。我在测试阶段将Excel设置为可见，并注意到打开它需要大约7秒钟。然后另外2个填10行。
我也在编写反向代码，从excel导入listview。为此，我使用了StreamReader对象，结果几乎是立即的。所以我认为更改导出的代码将允许我相同的速度。我试过这段代码：
FileStream srcFS;
srcFS = new FileStream(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory) + "\\testingout.csv", FileMode.CreateNew, FileAccess.Write);
StreamWriter srcWrt = new StreamWriter(srcFS, System.Text.Encoding.Default);
StringBuilder header = new StringBuilder();
header.Append("Name").Append(',')
.Append("CPU").Append(',')
.Append("RAM").Append(',')
.Append("IP Address").Append(',')
.Append("Port Group").Append(',')
.Append("Default Gateway").Append(',')
.Append("DNS").Append(',')
.Append("Description").Append(',')
.Append("Template").Append(',')
.Append("Host").Append(',')
.Append("Site").Append(',')
.Append("Folder").Append(',')
.Append("Datastore").Append(',')
.Append("Patch").Append(',')
.Append("HDD1Size").Append(',')
.Append("HDD1Format").Append(',')
.Append("HDD2Size").Append(',')
.Append("HDD2Format").Append(',')
.Append("HDD3Size").Append(',')
.Append("HDD3Format").Append(',')
.Append("HDD4Size").Append(',')
.Append("HDD4Format").Append(',')
.Append("HDD5Size").Append(',')
.Append("HDDFormat").Append(',');
srcWrt.WriteLine(header);
foreach (MyItem item in MyItems)
{
StringBuilder builder = new StringBuilder();
builder.Append(item.Name).Append(',')
.Append(item.CPU).Append(',')
.Append(item.RAM).Append(',')
.Append(item.IP).Append(',')
.Append(item.Subnet).Append(',')
.Append(item.PortGroup).Append(',')
.Append(item.Gateway).Append(',')
.Append(item.DNS).Append(',')
.Append(item.Description).Append(',')
.Append(item.Template).Append(',')
.Append(item.Host).Append(',')
.Append(item.Site).Append(',')
.Append(item.Folder).Append(',')
.Append(item.Datastore).Append(',')
.Append(item.Patch).Append(',')
.Append(item.HDD1Size).Append(',')
.Append(item.HDD1Format).Append(',')
.Append(item.HDD2Size).Append(',')
.Append(item.HDD2Format).Append(',')
.Append(item.HDD3Size).Append(',')
.Append(item.HDD3Format).Append(',')
.Append(item.HDD4Size).Append(',')
.Append(item.HDD4Format).Append(',')
.Append(item.HDD5Size).Append(',')
.Append(item.HDD5Format);
srcWrt.WriteLine(builder);
}
MessageBox.Show("Task Complete");
但似乎指数速度较慢，如40秒返回消息框。此外，我注意到即使循环完成，并显示消息，似乎流仍在写。如果我过快地打开文件，则说明＃34;另一个用户＆＃34;正在使用它。所以当文件可供我使用时，它实际上更接近一分钟。
我只是想知道为什么速度读取与使用FileStream写入的差异。这是我在实施时遇到的问题，还是这个已知的问题？如果要与Excel交互是可行的方法（我不是因为并非所有机器都安装了Excel）是否有办法缩短最初的6或7秒延迟？
答案 0 :(得分：1)
尝试将您的功能重写为：
StringBuilder builder = new StringBuilder();
builder.Append("Name").Append(',')
.Append("CPU").Append(',')
.Append("RAM").Append(',')
.Append("IP Address").Append(',')
.Append("Port Group").Append(',')
.Append("Default Gateway").Append(',')
.Append("DNS").Append(',')
.Append("Description").Append(',')
.Append("Template").Append(',')
.Append("Host").Append(',')
.Append("Site").Append(',')
.Append("Folder").Append(',')
.Append("Datastore").Append(',')
.Append("Patch").Append(',')
.Append("HDD1Size").Append(',')
.Append("HDD1Format").Append(',')
.Append("HDD2Size").Append(',')
.Append("HDD2Format").Append(',')
.Append("HDD3Size").Append(',')
.Append("HDD3Format").Append(',')
.Append("HDD4Size").Append(',')
.Append("HDD4Format").Append(',')
.Append("HDD5Size").Append(',')
.Append("HDDFormat").Append(',');
.Append(Environment.NewLine);
foreach (MyItem item in MyItems)
{
builder.Append(item.Name).Append(',')
.Append(item.CPU).Append(',')
.Append(item.RAM).Append(',')
.Append(item.IP).Append(',')
.Append(item.Subnet).Append(',')
.Append(item.PortGroup).Append(',')
.Append(item.Gateway).Append(',')
.Append(item.DNS).Append(',')
.Append(item.Description).Append(',')
.Append(item.Template).Append(',')
.Append(item.Host).Append(',')
.Append(item.Site).Append(',')
.Append(item.Folder).Append(',')
.Append(item.Datastore).Append(',')
.Append(item.Patch).Append(',')
.Append(item.HDD1Size).Append(',')
.Append(item.HDD1Format).Append(',')
.Append(item.HDD2Size).Append(',')
.Append(item.HDD2Format).Append(',')
.Append(item.HDD3Size).Append(',')
.Append(item.HDD3Format).Append(',')
.Append(item.HDD4Size).Append(',')
.Append(item.HDD4Format).Append(',')
.Append(item.HDD5Size).Append(',')
.Append(item.HDD5Format)
.Append(Environment.NewLine);
}
using(FileStream srcFS = new FileStream(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory) + "\\testingout.csv", FileMode.CreateNew, FileAccess.Write))
{
using(StreamWriter srcWrt = new StreamWriter(srcFS, System.Text.Encoding.Default))
{
srcWrt.WriteText(builder.);
}
}
我猜你写的每个循环都会减慢你的代码速度。如果你改为在一个批处理中写入文件，那么当字符串完成时。这通常是一个更好的选择