xml - 无法阻止 PowerShell 更改返回对象的类型

Question

当我从函数返回 XML 对象时，PowerShell 将其类型更改为 Object[] :



我在这里读到:
PowerShell changes return object's type
Preserving PowerShell function return type
https://www.experts-exchange.com/questions/27035513/How-to-stop-PowerShell-function-changing-return-type-of-ArrayList-or-string.html

如何防止它，他们都写了添加逗号,在返回应该解决它。

我试过:

return ,$computer

问题仍然存在。
它仍然返回我 Object[]输入而不是 XmlElement类型。

示例代码:

Function getComputerXML($doc){
    $computer  = $doc.CreateNode("element","Computer",$null)

    $computerSettings = $doc.CreateNode("element","ComputerSettings",$null)
    $computerSettings.SetAttribute("Name","HP") | Out-Null
    $computerSettings.InnerText = "someText"
    $computer.AppendChild($computerSettings)

    return $computer
}

Function main(){

   [xml]$doc = New-Object System.Xml.XmlDocument

   $computer = getComputerXML $doc
   #$computers.AppendChild($computer)
}

main

Answer 1

问题是函数输出consists of everything that isn't captured并且始终是 .NET 对象。

Function main(){

   [xml]$doc = New-Object System.Xml.XmlDocument

   $computer = getComputerXML $doc
   [void]$computers.AppendChild($computer)
}

您可以查看with/out的区别[void]像这样:

$computers| foreach {$_.GetType().Fullname}

The return keyword allows you to exit the function at any particular point, ... but we do not need to use the return keyword like we do in C style function.    You may also "optionally" specify an argument to the return statement that will cause the argument to be output just before returning.  "return $xy" does not mean that the functions only output is the contents of the $xyvariable. ...

You have to be diligent when you write a PowerShell function to ensure you get only the output you want.  This usually means redirecting unwanted output to $null (or optionally type casting the expression with the unwanted output to [void]).