通过System.Collections.Queue传递对象时丢失类型信息 [英] Losing type information when passing an object through a System.Collections.Queue

问题描述

从本质上讲，作为Powershell脚本的一部分，我需要实现广度优先搜索.因此，我需要队列，并且认为System.Collections.Queue与其他任何队列一样好.但是，当我从队列中取出一个对象时，Powershell会丢失对我添加到该对象的所有属性的跟踪.

As part of my Powershell script I need to, essentially, implement breadth-first search. So, I need queue and figured System.Collections.Queue is as good as any other queue. However, when I get an object out of the queue, Powershell loses track of any properties I've added to the object.

这是怎么回事?如何访问我的财产?

What's going on here? How do I access my property?

此示例演示了问题:

$object = new-object object
add-member -membertype noteproperty -name AnInteger -value 2 -inputobject $object
$queue = new-object system.collections.queue
$queue.enqueue($object)
$dequeued = $queue.dequeue()

# 1. True - both variables refer to the same object.
$object -eq $dequeued 
# 2. True - using the original variable, can access the property.
$object.AnInteger -ne $null
# 3. False. Err, What?
$dequeued.AnInteger -ne $null 

解决方案和更多问题

我发现了我的错误: add-member 修改了 PSObject 而不是Object的实例.好像它为我创建了一个在添加属性之前包装 $ object 的代码.因此，我需要创建一个 PSObject 或将出队的结果强制转换为 PSObject .

Solution and More Questions

I found my mistake: add-member modifies an instance of PSObject not Object. It looks like it created one for me to wrap $object before adding the property. So, I needed to either create a PSObject or cast the result of dequeue to PSObject.

我仍然不了解这里发生的一切.添加成员是否修改了 $ object 以引用其创建的 PSObject ?如果不是，那么Powershell运行时如何知道 $ object 实际上是 PSObject ? $ object.gettype().name 是 Object ，而不是 PSCustomObject .

I still don't understand everything that's going on here. Did add-member modify $object to refer to the PSObject it created? If not, how did the Powershell run-time know that $object was in fact a PSObject? $object.gettype().name is Object not PSCustomObject.

推荐答案

使用PsObject时，它可以工作.但是，我不知道为什么它不能在.NET对象上工作

When you use PsObject, it works. However, I have no idea why it doesn't work on the .NET Object

$object = new-object PsObject -property @{AnInteger=2}
$queue = new-object system.collections.queue
$queue.enqueue($object)
$dequeued = $queue.dequeue()

$object.Aninteger -eq $dequeued.AnInteger # returns True

其他.NET集合显然也是如此:

The same holds obviously for other .NET collections as well:

$mynum  = 10 | add-member noteproperty MySecret 12345 -pass
$mynum.mysecret
$list = New-Object collections.arraylist
$list.Add($mynum)
$list[0].mysecret

$list[0] | fl * -force # shows nothing
$mynum | fl * -force   # shows mysecret

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