PowerShell脚本发送SharePoint报表后删除文件提示被占用问题

问题原因 #

你遇到的文件占用错误，是因为System.Net.Mail.Attachment和MailMessage对象在发送邮件后没有释放文件句柄。即使SmtpClient.Send()执行完成，这些对象仍会保留对文件的锁定，导致后续删除操作失败。另外你脚本里的两个Do-While循环因为$condition未定义，根本不会执行，可以直接移除。

解决方案 #

发送邮件后，必须手动调用Attachment.Dispose()和MailMessage.Dispose()释放资源，或者使用PowerShell的using语句自动管理对象生命周期（推荐）。

修改后的完整脚本 #

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
cls; 
#Get the Web
$web = Get-SPWeb -identity "SharePoint URL"
 
#Get the Target List
$list = $web.Lists["SharePoint List"]
 
#Array to Hold Result - PSObjects
$ListItemCollection = @()

$date = (get-date).ToString("dd.MM.yyyy")
  
#Get All List items where Status is "In Progress"
$list.Items | Where-Object { $_["Stav_Požiadavka"] -match "Požadované"} | foreach {
    $ExportItem = New-Object PSObject
    $a = $_["Editor"] -replace ';','' -replace '#','' -replace '\d+',''
    $ExportItem | Add-Member -MemberType NoteProperty -name "Spracovatel" -value $_["Meno_Priezvisko_Spracovateľ"]
    $ExportItem | Add-Member -MemberType NoteProperty -Name "Vytvorene" -value $_["Created"]
    $ExportItem | Add-Member -MemberType NoteProperty -name "RodneCislo" -value $_["Rodn_x00e9___x010c__x00ed_slo_Klient"]
    $ExportItem | Add-Member -MemberType NoteProperty -name "Upravene" -value $_["Modified"]
    $ExportItem | Add-Member -MemberType NoteProperty -name "Upravil" -value $a
 
    #Add the object with property to an Array
    $ListItemCollection += $ExportItem
}
#Export the result Array to CSV file
$ListItemCollection | Export-CSV "c:\ListData.txt" -NoTypeInformation -Encoding utf8                  
 
#Dispose the web Object
$web.Dispose()
write-host "Export úspešné dokončený" -ForegroundColor Green

#Send export via SMTP
$fromaddress = "sender e-mail address"
$toaddress = "receiver e-mail address"
$Subject = "Export otvorených žiadostí v aplikácii UmrtieKlienta k "+$date
$body = "test"
$smtpserver = "SMTP server"
$attachmentPath = "c:\ListData.txt"

# 使用using语句自动管理资源，发送完成后自动释放文件句柄
using ($message = New-Object System.Net.Mail.MailMessage) {
    $message.From = $fromaddress
    $message.To.Add($toaddress)
    $message.IsBodyHtml = $True
    $message.Subject = $Subject
    $message.Body = $body

    using ($attach = New-Object Net.Mail.Attachment($attachmentPath)) {
        $message.Attachments.Add($attach)
        using ($smtp = New-Object Net.Mail.SmtpClient($smtpserver)) {
            $smtp.Send($message)
        }
    }
}

# 现在可以正常删除文件了
rm -fo $attachmentPath

write-host "Export odoslaný na určených príjemcov" -ForegroundColor Green

关键修改点 #

1. 移除了无意义的Do-While循环
2. 使用using语句包裹MailMessage、Attachment和SmtpClient对象，确保对象使用完毕后自动调用Dispose()释放资源，包括文件句柄
3. 把附件路径存为变量$attachmentPath，避免重复写路径

如果你的PowerShell版本低于5.1（不支持using语句），可以手动调用Dispose()替代：

# 发送邮件后手动释放资源
$attach.Dispose()
$message.Dispose()
$smtp.Dispose()

内容的提问来源于stack exchange，提问作者jck4real