Powershell腳本錯誤

Question

我試圖找出是否在網絡上啓用/禁用Windows防火牆，以掃描網絡並讓我知道防火牆服務是否啓用/禁用。

這裏是我使用的腳本，記住我大時間入門級：

function Get-FWState 
{ 
    param 
    (
     [int]$state 
    ) 

    switch ($state) 
    { 
     0 { return "Off" } 
     1 { return "On" } 
    } 
} 

if (-not (Get-Module ActiveDirectory)) 
{ 
    Import-Module ActiveDirectory 
} 

$computers = Get-ADComputer -Filter * 

ForEach ($computer in $computers) 
{ 
    try 
    { 
     $everythingOK = $True 

     $reg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $computer.Name) 

     $domkey = $reg.OpenSubkey("SYSTEM\\CurrentControlSet\\Services\\SharedAccess\\Parameters\\FirewallPolicy\\DomainProfile") 
     $domvalue = $domkey.GetValue("EnableFirewall") 

    } 
    catch 
    { 
     $everythingOK = $false 
     $_ 
    } 

    if ($everythingOK) 
    { 
     $stdkey = $reg.OpenSubkey("SYSTEM\\CurrentControlSet\\Services\\SharedAccess\\Parameters\\FirewallPolicy\\StandardProfile") 
     $stdvalue = $stdkey.GetValue("EnableFirewall") 

     $pubkey = $reg.OpenSubkey("SYSTEM\\CurrentControlSet\\Services\\SharedAccess\\Parameters\\FirewallPolicy\\PublicProfile") 
     $pubvalue = $pubkey.GetValue("EnableFirewall") 
    } 

    $obj = New-Object -TypeName PSObject 
    $obj | Add-Member -MemberType NoteProperty -Name 'HostName' -Value $computer.Name 
    $obj | Add-Member -MemberType NoteProperty -Name 'DomainProfile' -Value $(Get-FWState -state $domvalue) 
    $obj | Add-Member -MemberType NoteProperty -Name 'StandardProfile' -Value $(Get-FWState -state $stdvalue) 
    $obj | Add-Member -MemberType NoteProperty -Name 'PublicProfile' -Value $(Get-FWState -state $pubvalue) 

    Write-Output $obj 
} 

當我運行該腳本，我得到了以下錯誤消息。

You cannot call a method on a null-valued expression. 
At C:\Scripts\Firewall.ps1:46 char:37 
+   $pubvalue = $pubkey.GetValue <<<< ("EnableFirewall") 
    + CategoryInfo   : InvalidOperation: (GetValue:String) [], RuntimeException 
    + FullyQualifiedErrorId : InvokeMethodOnNull 

You cannot call a method on a null-valued expression. 
At C:\Scripts\Firewall.ps1:46 char:37 
+   $pubvalue = $pubkey.GetValue <<<< ("EnableFirewall") 
    + CategoryInfo   : InvalidOperation: (GetValue:String) [], RuntimeException 
    + FullyQualifiedErrorId : InvokeMethodOnNull 

Answer 1

它說問題是在空表達式上調用方法。您確定「$ pubkey」不爲空，因此，

$pubkey = $reg.OpenSubkey("SYSTEM\\CurrentControlSet\\Services\\SharedAccess\\Parameters\\FirewallPolicy\\PublicProfile") 

返回45行的值嗎？