Question

我遇到以下代码的问题

foreach ($ex in ("foo", "bar", "baz")) {
$timer = New-Object Timers.timer
$taction =  {
    Write-Host "Timer fired for: $ex"
}
$timer.Interval = 1000 
$timer.AutoReset = $false
$timer.Start()

Register-ObjectEvent -InputObject $timer -EventName elapsed -SourceIdentifier "$ex" -Action $taction

}

此代码提供以下输出

Timer fired for: baz
Timer fired for: baz
Timer fired for: baz

但我想拥有它foo，bar和baz。问题似乎是$ ex变量最终被所有Timers读取，所以无论它有什么价值，它们都得到它。如何在$ taction中复制$ ex的值以使其唯一？

Answer 1

尝试使用[scriptblock]::Create()，在创建时评估参数：

foreach ($ex in ("foo", "bar", "baz"))
{

$timer = New-Object Timers.timer
$taction =  [scriptblock]::create("Write-Host Timer fired for: $ex")

$timer.Interval = 1000 
$timer.AutoReset = $false
$timer.Start()

Register-ObjectEvent -InputObject $timer -EventName elapsed -SourceIdentifier $ex  -Action $taction
}

强制立即评估powershell脚本（按值复制变量，而不是引用）

1 个答案: