Powershell：如何将结果添加到数组（ForEach-Object -Parallel）

Question

我知道，通过参数$using:foo我可以在 Powershell 7 及更高ForEach-Object -Parallel中运行ForEach-Object -Parallel时使用来自不同运行空间的变量。

但是如何将结果添加回变量？ 通用参数+=和$using:将不起作用。

例如：

$AllSubs = Get-AzSubscription
$Date = (Get-Date).AddDays(-2).ToString("yyyy-MM-dd")
$Costs = @()

$AllSubs | Sort-Object -Property Name | ForEach-Object -Parallel {
    Set-AzContext $_.Name | Out-Null
    Write-Output "Fetching Costs from '$($_.Name)' ..."
    $using:Costs += Get-AzConsumptionUsageDetail -StartDate $using:Date -EndDate $using:Date -IncludeAdditionalProperties -IncludeMeterDetails -ErrorAction SilentlyContinue
}

输出：

The assignment expression is not valid. The input to an assignment operator must be an object that is
     | able to accept assignments, such as a variable or a property.

Answer 1

您必须将操作拆分为两个并将从$using:Costs获得的引用分配给局部变量，并且您必须使用与 PowerShell 的可调整大小的数组不同的数据类型 - 最好是并发（或线程安全）类型：

$AllSubs = Get-AzSubscription
$Date = (Get-Date).AddDays(-2).ToString("yyyy-MM-dd")

# Create thread-safe collection to receive output
$Costs = [System.Collections.Concurrent.ConcurrentBag[psobject]]::new()

$AllSubs | Sort-Object -Property Name | ForEach-Object -Parallel {
    Set-AzContext $_.Name | Out-Null
    Write-Output "Fetching Costs from '$($_.Name)' ..."

    # Obtain reference to the bag with `using` modifier 
    $localCostsVariable = $using:Costs

    # Add to bag
    $localCostsVariable.Add($(Get-AzConsumptionUsageDetail -StartDate $using:Date -EndDate $using:Date -IncludeAdditionalProperties -IncludeMeterDetails -ErrorAction SilentlyContinue))
}