如何在變量賦值期間抑制PowerShell錯誤消息

Question

有什麼辦法可以抑制這個錯誤。相反，這種醜陋的和長期的錯誤，我想捕捉返回代碼值（$？），以決定成敗

PS C:\> $str ="<p> Hi </p>" 
    PS C:\> $data = [xml]$str 
    PS C:\> $? 
    True 
    PS C:\> 
    PS C:\> $str ="<p> Hi <p>" 
    PS C:\> $data = [xml] $str 
    Cannot convert value "<p> Hi <p>" to type "System.Xml.XmlDocument". Error: "Unexpected end of file has occurred. The following elements are 
    not closed: p, p. Line 1, position 11." 
    At line:1 char:1 
    + $data = [xml] $str 
    + ~~~~~~~~~~~~~~~~~~ 
     + CategoryInfo   : InvalidArgument: (:) [], RuntimeException 
     + FullyQualifiedErrorId : InvalidCastToXmlDocument 

    PS C:\> $data = [xml] $str 2> $null 
    Cannot convert value "<p> Hi <p>" to type "System.Xml.XmlDocument". Error: "Unexpected end of file has occurred. The following elements are 
    not closed: p, p. Line 1, position 11." 
    At line:1 char:1 
    + $data = [xml] $str 2> $null 
    + ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
     + CategoryInfo   : InvalidArgument: (:) [], RuntimeException 
     + FullyQualifiedErrorId : InvalidCastToXmlDocument 

    PS C:\> 
    PS C:\> $? 
    False 
    PS C:\> 

Answer 1

放置一個嘗試捕捉周圍的命令

try {$data = [xml] $str } catch {}