blocks|key|4645770|text|对我来说，这将返回所有进程，就像简单的get-process命令一样：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4645771|try
{
+++$a+=+get-process
}
catch
{
++++write-error+"Some+error+occurred"
}

$a|code-block|syntax|javascript|4645772|entityMap^0|J|B|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

For me this return all the processes as simple <code>get-process</code> command does:

<pre><code>try
{
 $a = get-process
}
catch
{
 write-error "Some error occurred"
}

$a
</code></pre>

blocks|key|3006283|text|正如@Christian指出的那样，它应该以你拥有的方式工作得很好。如果没有填充$x，则可能是Get-X没有返回任何内容，或者发生了错误。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3006284|您可以始终使用在顶部声明变量的模式：|3006285|$a+=+<default+value,+or+$null>
try
{
+++$a+=+get-process
}
catch
{
++++write-error+"Some+error+occurred"
}
$a|code-block|syntax|javascript|3006286|entityMap^0|14|2|1B|5|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|U|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

As @Christian notes, it should work fine the way you have it. If <code>$x</code> is not getting populated, perhaps <code>Get-X</code> is not returning anything, or an error is occurring.

You can always go with the pattern of declaring the variable up top:

<pre><code>$a = &lt;default value, or $null&gt;
try
{
 $a = get-process
}
catch
{
 write-error "Some error occurred"
}
$a
</code></pre>

blocks|key|3006311|text|我刚碰到这个，它看起来像是个bug。在try块外声明变量并不能解决作用域问题。一旦您离开try块，$a的值就会重置为您进入try块之前的值。因此，如果您想在执行try{}之后访问$a，则需要在try+{}块中以$global:a的身份访问它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3006312|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I just ran into this and it looks like a bug. Declaring the variable outside try block does not solve the scope issue. As soon you leave the try block value of $a gets reset to what it was before you entered try block. so if you want to access $a after executing try{} you need to access it as $global:a inside the try {} block.

blocks|key|2563291|text|为了使try语句能够实际捕获不存在的变量的Get-Variable失败。我必须添加-ErrorAction开关。默认的ErrorAction是继续，这不允许try语句捕获错误。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2563292|$testName+=+Get-Variable+-Name+$variableName+-ErrorAction+Stop+|code-block|syntax|javascript|2563293|entityMap^0|15|C|1N|B|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

For the try statement to actually catch the failure of Get-Variable of a variable that does not exist. I had to add the <code>-ErrorAction</code> switch. The default <code>ErrorAction</code> is to continue, this did not allow the try statement to catch the error.

<pre><code>$testName = Get-Variable -Name $variableName -ErrorAction Stop 
</code></pre>

blocks|key|2560717|text|我在前面的回答中添加了一个注释，但我觉得有必要发布一个示例Powershell函数(在类的上下文中)，以演示使用作用域(在我的例子中是$private)解决了这个问题：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2560718|[String[]]+static+GetSRVHostPort([String]$srvRecord)+{
++++++++[String]+$private:myHost,+$private:myPort
++++++++try+{
++++++++++++$private:myHost,+$private:myPort+=+Resolve-DnsName+-Type+'srv'+$srvRecord+%7C+ForEach-Object+{+$_.Name,+$_.Port+}
++++++++}+catch+{
++++++++++++Write-Output("Exception+thrown+whilst+resolving+DNS+SRV+record+[$srvRecord]:+$_")
++++++++}
++++++++return+$private:myHost,+$private:myPort
++++}|code-block|syntax|javascript|2560719|有关作用域的更多细节，请访问：https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_scopes?view=powershell-6#scope-modifiers|2560720|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_scopes?view=powershell-6#scope-modifiers^0|1V|8|0|0|F|3L|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

I added a comment to a previous answer but felt the need to post an example Powershell function (within the context of a class) to demonstrate that using scoping (<code>$private</code> in my case) addresses this issue:

<pre><code>[String[]] static GetSRVHostPort([String]$srvRecord) {
 [String] $private:myHost, $private:myPort
 try {
 $private:myHost, $private:myPort = Resolve-DnsName -Type 'srv' $srvRecord | ForEach-Object { $_.Name, $_.Port }
 } catch {
 Write-Output("Exception thrown whilst resolving DNS SRV record [$srvRecord]: $_")
 }
 return $private:myHost, $private:myPort
 }
</code></pre>

For futher details of scopes: <a href="https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_scopes?view=powershell-6#scope-modifiers" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_scopes?view=powershell-6#scope-modifiers</a>

I have below piece of code , where I am trying to access a variable defined in try but it's not accessible , what could be done to fix it.

<pre><code> try{
 $X = get-X 
 }
 catch
 {
 Manage exception
 }

 write-host $X
</code></pre>

How to access variables defined in try catch scope in Powershell

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有下面的一段代码，我试图访问一个在try中定义的变量，但它无法访问，可以做些什么来修复它。  try{       $X = get-X      }  catch     {            Manage exception     }   write-host $X

问如何在Powershell中访问try catch作用域中定义的变量
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问如何在Powershell中访问try catch作用域中定义的变量EN