Question

我正在做一些关于管道的学习实验，我已经建立了自己的3个功能：The-Getter，Do-Something，Output-Somewhere。

使用我的getter函数，我正在尝试输出只有name属性的3个对象。除了我的结果将被重复（显示两次）之外，它有点工作。

我想知道我在这里做错了什么：

function The-Getter {
[CmdletBinding()]
Param()

begin{
Write-Verbose -Message 'Entering the begin bloc of The-Getter'
$a = 'BMW X3'
$b = 'BMW X4'
$c = 'BMW X6'
}

process{
Write-Verbose -Message "Entering the process bloc of The-Getter with object $_"
$Collection = @()
$obj1 = New-Object –typename PSObject
$obj1 | Add-Member –membertype NoteProperty –name Name –value ($a) –passthru
$Collection += ($obj1)

$obj2 = New-Object –typename PSObject
$obj2 | Add-Member –membertype NoteProperty –name Name –value ($b) –passthru
$Collection += ($obj2)

$obj3 = New-Object –typename PSObject
$obj3 | Add-Member –membertype NoteProperty –name Name –value ($c) –passthru
$Collection += ($obj3)

Return $Collection
}

end{
Write-Verbose -Message 'Entering the end bloc of The-Getter'
}
}

输出是：

PS C:\> The-Getter

Name
----
BMW X3
BMW X4
BMW X6
BMW X3
BMW X4
BMW X6

感谢您的时间。

Answer 1

问题来自您调用Add-Member并返回Object。由于您不对返回的对象执行任何操作，因此会打印。

如果您将$Collection +=与Add-Member行合并，问题就会消失：

$obj2 = New-Object –typename PSObject
$Collection += $obj2 | Add-Member –membertype NoteProperty –name Name –value ($b) –passthru

但实际上，你可以完全摆脱$Collection：

process{
Write-Verbose -Message "Entering the process bloc of The-Getter with object $_"
$obj1 = New-Object –typename PSObject
$obj1 | Add-Member –membertype NoteProperty –name Name –value ($a) –passthru
$obj2 = New-Object –typename PSObject
$obj2 | Add-Member –membertype NoteProperty –name Name –value ($b) –passthru
$obj3 = New-Object –typename PSObject
$obj3 | Add-Member –membertype NoteProperty –name Name –value ($c) –passthru
}

为什么我的脚本会将对象返回两次？

1 个答案: