PowerShell避免使用脚本范围的变量

我编写了一个函数来检查主机是否在线或离线，然后返回$true或$false。此函数运行完美，我想通过查看是否有可能删除脚本范围的变量（如$Script:arrayCanPingResult和）来对其进行一些改进$script:tmpPingCheckServers。

我为什么要这个？当我在foreach循环中调用函数时，通常使用开关，-Remember这样它就不会两次检查同一主机。为了能够正确使用此功能，我必须通过将两个变量都声明为空（$Script:arrayCanPingResult=$script:tmpPingCheckServers=@{}）来开始使用该功能的所有脚本。我可以想象人们会忘记在脚本中放入第一行，并且在PowerShell ISE编辑器中进行多次测试时，如果已经在ISE中对主机进行了一次检查（F5），它将不会在第二次运行中再次进行测试。 。

有没有一种方法可以避免在这种情况下使用脚本范围的变量？因此，我们不需要在新脚本的开头将它们声明为空吗？如果可能的话，那就太好了，因为这样我们就可以在自定义模块中包含此功能。

与往常一样，感谢您的建议或帮助。在你们这里​​我真的学到了很多东西。

# Function to check if $Server is online
Function Can-Ping ($Server,[switch]$Remember) {

    $PingResult = {
          # Return $true or $false based on the result from script block $PingCheck
          foreach ($_ in $Script:arrayCanPingResult) { 
                   # Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: $_ " -ForegroundColor Green
                   if ($Server -eq $($_.Split(",")[0])) {

                   #Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: We will return $($_.Split(",")[1])" -ForegroundColor Green
                    return $($_.Split(",")[1])  
                   } 
          }
    }

    $PingCheck = {

        $Error.Clear()

        if (Test-Connection -ComputerName $Server -BufferSize 16 -Count 1 -ErrorAction 0 -quiet) { # ErrorAction 0 doesn't display error information when a ping is unsuccessful

            Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Ping test ok" -ForegroundColor Gray; $Script:arrayCanPingResult+=@("$Server,$true"); return
        } 
        else {
            $Error.Clear()
            Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Ping test FAILED" -ForegroundColor Gray

            Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Flushing DNS" -ForegroundColor Gray
            ipconfig /flushdns | Out-Null

            Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Registering DNS" -ForegroundColor Gray
            ipconfig /registerdns | Out-Null

            Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: NSLookup" -ForegroundColor Gray
            nslookup $Server | Out-Null # Suppressing error here is not possible unless using '2> $null', but if we do this, we don't get $true or $false for the function so '| Out-Null' is an obligation
            if (!$?) {
                Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: NSlookup can't find the host '$Server', DNS issues or hostname incorrect?" -ForegroundColor Yellow
                # Write-Host $Error -ForegroundColor Red
                if ($SendMail) {
                    Send-Mail $MailTo "FAILED Ping test" "$(Get-TimeStamp) NSlookup can't find the host '$Server', hostname incorrect or DNS issues?" "<font color=`"red`">$error</font>"
                }
                $script:arrayCanPingError += "ERROR | $(Get-TimeStamp) Ping test failed: NSlookup can't find the host '$Server', hostname incorrect or DNS issues?$error"
                $script:HTMLarrayCanPingError += "ERROR | $(Get-TimeStamp) Ping test failed:<br>NSlookup can't find the host '$Server', hostname incorrect or DNS issues?<br><font color=`"red`">$error</font>"
                $Script:arrayCanPingResult+=@("$Server,$false")
                return
                }
            else {
                Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Re-pinging '$Server'" -ForegroundColor Gray
                if (Test-Connection -ComputerName $Server -BufferSize 16 -Count 1 -ErrorAction 0 -Quiet) {
                   Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Ping test ok, problem resolved" -ForegroundColor Gray
                   $Script:arrayCanPingResult+=@("$Server,$true")
                   return
                }
                else {
                      Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: DNS Resolving is ok but can't connect, server offline?" -ForegroundColor Yellow
                      if ($SendMail) {
                          Send-Mail $MailTo "FAILED Ping test" "$error" "DNS Resolving is ok but can't connect to $Server, server offline?"
                      } 
                      $script:arrayCanPingError += "ERROR Ping test failed: DNS Resolving is ok but can't connect to $Server, server offline?$error"
                      $script:HTMLarrayCanPingError += "ERROR Ping test failed: DNS Resolving is ok but can't connect to $Server, server offline?<br><font color=`"red`">$error</font>"
                      $Script:arrayCanPingResult+=@("$Server,$false")
                      return
                }
            }
        }
    }

    # Call the script block $PingAction every time, unless the switch $Remember is provided, than we only check each server once
    if ($Remember) {
        Write-Host "$(Get-TimeStamp) $Server > Function Can-Ping: Switch '-Remember' detected" -ForegroundColor Gray
        While ($tmpPingCheckServers -notcontains $Server) { 
                  &$PingCheck
                  $script:tmpPingCheckServers = @($tmpPingCheckServers+$Server) #Script wide variable, otherwise it stays empty when we leave the function / @ is used to store it as an Array (table) instead of a string
        }
        &$PingResult
    } 
    else {
          &$PingCheck
          &$PingResult
    }
}