Register-ObjectEvent cmdlet 在 Powershell 上无法正常工作，但在 ISE 上工作

Question

我正在使用 Powershell 脚本来监视文件夹，当创建新项目时，脚本需要将该文件复制到另一个文件夹。

我遇到的问题是，当我在 Powershell ISE 中执行它时，它运行良好，但是在 Powershell 上执行它时，它仅在 Powershell 窗口打开的时间段内有效（> 1 秒）。

我尝试将 sleep 命令放在最后，发现只有在脚本结束时才会执行操作，在这种情况下，当我在 Powershell 中按 CTRL+C 停止脚本时，我应该执行的操作创建的项目一起执行。

不知道是我做错了什么还是只是误解了什么。

这是我用来测试它的脚本：

$Watcher = New-Object System.IO.FileSystemWatcher
$Watcher.path = "\\192.168.5.127\data\TestWatcher"
$Destination = "C:\TestWatcher"
$Watcher | Get-Member -MemberType Event
$Watcher.EnableRaisingEvents = $true

$action = {
    $path = $event.SourceEventArgs.FullPath
    $name = $event.SourceEventArgs.Name
    $changetype = $event.SourceEventArgs.ChangeType
    Write-Host "File $name at path $path was $changetype at $(get-date)"
    Copy-Item $Watcher.path $Destination
}

Register-ObjectEvent $Watcher 'Created' -Action $action

任何帮助或建议将不胜感激。

此致，

Answer 1

Gregor y在评论中提供了关键提示：

您可以在脚本末尾使用Wait-Event调用来无限期地等待永远不会到达的事件，这使您的脚本保持运行，但是 - 与Start-Sleep不同 -不会阻止通过传递给Register-ObjectEvent的脚本块处理事件Register-ObjectEvent的-Action参数：

$Watcher = New-Object System.IO.FileSystemWatcher
$Watcher.path = "\\192.168.5.127\data\TestWatcher"
$Destination = "C:\TestWatcher"
$Watcher.EnableRaisingEvents = $true

$action = {
    $path = $event.SourceEventArgs.FullPath
    $name = $event.SourceEventArgs.Name
    $changetype = $event.SourceEventArgs.ChangeType
    Write-Host "File $name at path $path was $changetype at $(get-date)"
    Copy-Item $Watcher.path $Destination
}

# Register the event with a self-chosen name passed to -SourceIdentifier
# and an -Action script block.
$null = 
  Register-ObjectEvent $Watcher Created -SourceIdentifier FileWatcher -Action $action

# Now wait indefinitely for an event with the same source identifier to arrive.
# NONE will ever arrive, because the events are handled via the -Action script block.
# However, the call will prevent your script from exiting, without
# blocking the processing of events in the -Action script block.
Wait-Event -SourceIdentifier FileWatcher

---

或者，不用-Action脚本块并在Wait-Event循环中处理事件：

$Watcher = New-Object System.IO.FileSystemWatcher
$Watcher.path = "\\192.168.5.127\data\TestWatcher"
$Destination = "C:\TestWatcher"
$Watcher.EnableRaisingEvents = $true

# Register the event with a self-chosen name passed to -SourceIdentifier
# but WITHOUT an -Action script block.
$null = Register-ObjectEvent $Watcher 'Created' -SourceIdentifier FileWatcher

# Now use Wait-Event with the chosen source identifier to
# to indefinitely receive and then process the events as they 
# become available.
while ($event = Wait-Event -SourceIdentifier FileWatcher) {
  $path = $event.SourceEventArgs.FullPath
  $name = $event.SourceEventArgs.Name
  $changetype = $event.SourceEventArgs.ChangeType
  Write-Host "File $name at path $path was $changetype at $(Get-Date)"
  Copy-Item $Watcher.path $Destination
  $event | Remove-Event # Note: Events must be manually removed.
}