powershell - 如何从 Switch 语句中退出 While 循环

Question

在 PowerShell 中，如何退出嵌套在 switch 语句中的 while 循环，而不是立即执行 while 之后的代码堵塞？我似乎无法弄清楚。到目前为止，我尝试过的所有操作都会导致执行该代码块。

这是我想要完成的:

1. 检查文件是否存在并通知用户文件是否存在检测到。
2. 每 10 秒检查一次并通知用户
3. 如果没有检测到文件，则退出循环切换，继续第 2 步
4. 如果 30 秒后仍然检测到文件，则超时并退出整个脚本。

代码如下:

try {
    #Step 1
    $Prompt = <Some Notification Dialog with two buttons>
    switch ($Prompt){
        'YES' {
            # Display the Windows Control Panel

            #Wait for user to manually uninstall an application - which removes a file from the path we will check later.
            $Timeout = New-Timespan -Seconds 30
            $Stopwatch = [Dispatch.Stopwatch]::StartNew()

            while ($Stopwatch.elapsed -lt $Timeout) {
                if (Test-Path -Path "C:\SomeFile.exe" -PathType Leaf) {
                    Write-Host "The file is still there, remove it!"
                    return
                }
                Start-Sleep 10
            }

            #After timeout is reached, notify user and exit the script
            Write-Host "Timeout reached, exiting script"
            Exit-Script -ExitCode $mainExitCode #Variable is declared earlier in the script
        }
        'NO' {
            # Do something and exit script
        }
    }

    # Step 2
    # Code that does something here

    # Step 3
    # Code that does something here
} catch {
    # Error Handling Code Here
}

Answer 1

您可以使用带标签的 break 来退出特定循环(switch 语句算作一个循环)，请参阅 about_break .

$a = 0
$test = 1
:test switch ($test) {
    1 {
        Write-Output 'Start'
        while ($a -lt 100)
        {
            Write-Output $a
            $a++
            if ($a -eq 5) {
                break test
            }
        }
        Write-Output 'End'
    }
}
Write-Output "EoS"