PowerShell的 - 如何美元的启动工作一个脚本块p $ P-评估变量 [英] Powershell - how to pre-evaluate variables in a scriptblock for Start-Job

问题描述

我要在PowerShell中使用的后台作业。

I want to use background jobs in Powershell.

如何使在脚本块定义的时刻评估变量？

How to make variables evaluated at the moment of ScriptBlock definition?

$v1 = "123"
$v2 = "asdf"

$sb = {
    Write-Host "Values are: $v1, $v2"
}

$job = Start-Job -ScriptBlock $sb

$job | Wait-Job | Receive-Job

$job | Remove-Job

我得到印$ v1和v2的$空值。我怎样才能让他们在（传递给）的脚本块进行评估，并因此对后台作业？

I get printed empty values of $v1 and $v2. How can I have them evaluated in (passed to) the scriptblock and so to the background job?

推荐答案

一种方法是使用[脚本块] :: Create方法使用的局部变量的expanadable字符串创建脚本块：

One way is to use the [scriptblock]::create method to create the script block from an expanadable string using local variables:

$v1 = "123"
$v2 = "asdf"

$sb = [scriptblock]::Create("Write-Host 'Values are: $v1, $v2'")

$job = Start-Job -ScriptBlock $sb

的另一种方法是设置在InitializationScript变量：

Another method is to set variables in the InitializationScript:

$Init_Script = {
$v1 = "123"
$v2 = "asdf"
}

$sb = {
    Write-Host "Values are: $v1, $v2"
}

$job = Start-Job -InitializationScript $Init_Script -ScriptBlock $sb 

第三个选项是使用-ArgumentList参数：

A third option is to use the -Argumentlist parameter:

$v1 = "123"
$v2 = "asdf"

$sb = {
    Write-Host "Values are: $($args[0]), $($args[1])"
}

$job = Start-Job  -ScriptBlock $sb -ArgumentList $v1,$v2

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