PowerShell 中的去抖动功能

Question

我正在尝试在 PowerShell 中创建一个简单的去抖动函数。这是我到目前为止所拥有的。

# timer.ps1
# Define debounce function
Function New-Debounce {
    param(
        [scriptblock]$ScriptBlock,
        [int]$DelayMilliseconds
    )
    
    $timer = $null
    $id = $null

    return {
        # reset timer
        if ($timer) { 
            $timer.Stop() 
            $timer.Dispose()
        }

        $timer = [System.Timers.Timer]::new($DelayMilliseconds)
        # only fire once
        $timer.AutoReset = $false

        $timer.Start()

        # Listen for the Elapsed event and execute our script block when it occurs
        $id = Register-ObjectEvent `
            -InputObject $timer `
            -EventName "Elapsed" `
            -SourceIdentifier "Timer.Debounce" `
            -Action { Write-Host "Hello!"; & $ScriptBlock }
    }.GetNewClosure()
}

$f = New-Debounce -ScriptBlock { Write-Host "There" } -DelayMilliseconds 1000
& $f

# # Keep the process alive so the timer can do its thing
for ($i = 0; $i -lt 5; $i++) {
    Start-Sleep -Seconds 1
}

Unregister-Event "Timer.Debounce"

运行timer.ps1总是输出“Hello”，但从不输出“There”，我不确定为什么。

为什么当计时器触发时我传递的 $ScriptBlock 不会被执行？您将如何改进这段代码？

Answer 1

使用

-MessageData

将

$ScriptBlock

传递到操作块：

# Listen for the Elapsed event and execute our script block when it occurs
$registerObjectEventSplat = @{
    InputObject      = $timer
    EventName        = 'Elapsed'
    SourceIdentifier = 'Timer.Debounce'
    MessageData      = $ScriptBlock
    Action           = { Write-Host 'Hello!'; & $event.MessageData }
}

$id = Register-ObjectEvent @registerObjectEventSplat