将Excel另存为CSV格式文件

直接将Excel另存为CSV，速度很快：

$FilePath_Public_ip_maps_infos="D:\My Documents\Work\IP映射表.xlsx"

$Excel = New-Object -Com Excel.Application
$Excel.visible = $False
$Excel.displayalerts=$False
$WorkBook = $Excel.Workbooks.Open($FilePath_Public_ip_maps_infos)
#保存为CSV格式，需要设置参数值为6
$Workbook.SaveAs("D:\My Documents\Work\Public_ip_maps_infos22.csv",6)
$Excel.quit()

逐行读取Excel，然后将其保存为CSV，效率很低：

#读取负载均衡信息表
$strpath="D:\My Documents\Work\IP映射表.xlsx"
$excel=new-object -comobject excel.application
$WorkBook = $excel.Workbooks.Open($strpath)
$WorkSheet = $WorkBook.Worksheets.Item(1)
#已用行数
$usedrows = $worksheet.usedrange.rows.count
$Public_ip_maps_info = $Public_ip_maps_infos = $null
$Public_ip_maps_infos = @()
For($i=2;$i -le $usedrows;$i++)
{
 $Public_ip_maps_info = ""|Select public_ip,internal_ip,is_vip
 $Public_ip_maps_info.public_ip = $WorkSheet.Cells.Item($i,2).value2
 $Public_ip_maps_info.internal_ip = $WorkSheet.Cells.Item($i,3).value2
 $Public_ip_maps_info.is_vip = $WorkSheet.Cells.Item($i,4).value2
 $Public_ip_maps_infos += $Public_ip_maps_info
}
$Public_ip_maps_infos
$excel.Quit()
$WorkSheet =$null
$WorkBook = $null
$excel = $null
[GC]::Collect()

将CSV另存为Excel，参考：

http://www.pstips.net/converting-csv-to-excel-file.html