将字符串转换为 PSCustomObject

Question

我遇到的问题源于将 PSCustomObject 作为参数传递给 Start-Process cmdlet（我实质上是启动一个新的 PowerShell 进程以异步方式运行脚本来自调用脚本）。尽管该参数定义为 PSCustomObject 类型，但出于某种原因它被接受为字符串，因此看起来我需要将其转换回 PSCustomObject 才能访问任何属性。

这是我的调用脚本的必要部分：

# Convert JSON object to PowerShell object
$payload = ConvertFrom-Json $body

Write-Host $payload
## Returns exactly the following PsCustomObject:

## @{os=Windows Server Datacenter 2016; vmName=sbtestvm; diskType=Managed; username=testuser;
## password=Pa55w.rd1234; location=West Europe; size=Standard_D1;
## requestType=0; sender=test}

Write-Host $payload.os
## Returns: Windows Server Datacenter 2016

# Fire up new worker shell asynchronously
Start-Process powershell.exe -ArgumentList '-NoExit', "$PSScriptRoot\ServiceBus-AsyncWorker.ps1", "'$payload'"  # -Windowstyle Hidden

我执行的脚本：

Param(
    [Parameter(Mandatory=$True)]
    [PSCustomObject]$Request
)

# Import RequestHandler module to deal with processing service bus requests
Import-Module $PSScriptRoot\RequestHandler\RequestHandler.psm1

Write-Host $Request
## Returns exactly the same as 'Write-Host $payload' in the calling script

Write-Host $Request.os
## Returns empty string

Write-Host $Request.GetType()
## Returns System.String <--- This is the issue

长话短说：有没有办法首先阻止此对象被自动解析为字符串？如果不是 - 如何将此字符串转换回相关对象类型？

Answer 1

Start-Process powershell.exe 启动一个新的 PowerShell 进程。您不能跨进程边界传递 PowerShell 对象。

你可以改变

Start-Process powershell.exe -ArgumentList '-NoExit', "$PSScriptRoot\ServiceBus-AsyncWorker.ps1", "'$payload'"

到

$PSScriptRoot\ServiceBus-AsyncWorker.ps1 $payload

避免创建新进程，但那样会运行脚本在同一个 window。

如果您需要运行从控制台分离脚本，您可以运行它作为 background job:

$job = Start-Job -ScriptBlock {
    Param($Path, $Data)
    & "$Path\ServiceBus-AsyncWorker.ps1" $Data
} -ArgumentList $PSScriptRoot, $payload

否则在生成新进程时需要以序列化形式传递参数（例如原始 JSON）：

Start-Process powershell.exe -ArgumentList '-NoExit', "$PSScriptRoot\ServiceBus-AsyncWorker.ps1", "`"$body`""

然后（重新）从字符串创建对象：

Param(
    [Parameter(Mandatory=$true)]
    [string]$Json
)

# Import RequestHandler module to deal with processing service bus requests
Import-Module $PSScriptRoot\RequestHandler\RequestHandler.psm1

$Request = ConvertFrom-Json $Json
...

将字符串转换为 PSCustomObject

Convert string to PSCustomObject

powershell

casting

start-process