如the answer that you took the code in the question from所示：

• 在PowerShell中通过try / catch / finally statement的finally块处理Ctrl-C限制了您的 * 清理 * 操作-您的脚本将 * 总是 * 终止。
• 如果您需要 * 拦截 *Ctrl-C，以便可以选择 * 防止 * 终止，则需要使用[Console]::TreatControlCAsInput= $true的自定义键盘轮询循环，如this answer所示，并在下面的代码上下文中说明。

这种方法还意味着您正在调用PowerShell脚本的批处理文件不会看到Ctrl-C键，因此不会显示可怕的Terminate batch job (Y/N)?提示符，该提示符无法被抑制（请参阅this answer）。
这里有一个简化的概念证明，展示了核心技术;它循环CA。10秒，在此期间检测Ctrl-C键：

try {
  # Make sure that [Console]::ReadKey() can read Ctrl-C as a regular keypress
  # instead of getting terminated by it.
  [Console]::TreatControlCAsInput = $true
  foreach ($i in 1..100) { # Sample loop that runs for ca. 10 secs.
    Write-Host -NoNewline . # Visualize the passage of time.
    # Check for any keyboard input.
    if ([Console]::KeyAvailable) {
      # Consume the key without displaying it.
      $key = [Console]::ReadKey($true)
      # Check if it represents Ctrl-C
      $ctrlCPressed = $key.Modifiers -eq 'Control' -and $key.Key -eq 'C'
      if ($ctrlCPressed) {
        Write-Verbose -Verbose 'Ctrl-C was pressed'
        # ... take action here.
      }
    }
    # Sleep a little, but not too long, so that 
    # keyboard input checking remains responsive.
    Start-Sleep -Milliseconds 100
  }
}
finally {
  # Restore normal Ctrl-C behavior.
  [Console]::TreatControlCAsInput = $false
}

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您的代码上下文中的完整解决方案：

• 请注意，它包含一个R（恢复）choice.exe选项，可让您恢复当前的关机计划并关机。

# Determine the path to a file in which information about a pending
# shutdown is persisted by this script.
$lastScheduleFile = Join-Path $env:TEMP ('~{0}_Schedule.txt' -f [IO.Path]::GetFileNameWithoutExtension($PSCommandPath))

[datetime] $shutdownTime = 0
# First, see if this script previously scheduled a shutdown.
try { 
  $shutdownTime = ([datetime] (Get-Content -ErrorAction Ignore $lastScheduleFile)).ToUniversalTime()
}
catch {}
# If the time is in the past, by definition it doesn't reflect the true pending shutdown time, so we ignore it.
if ($shutdownTime -lt [datetime]::UtcNow) { 
  $shutdownTime = 0 
}
else {
  # Warn that the retrieved shutdown time isn't *guaranteed* to be correct.
  Write-Warning @'
The pending shutdown time is assumed to be what *this* script last requested, 
which is not guaranteed to be the true time, nor is it guaranteed that a shutdown is even still pending.
'@
}
$shutdownAlreadyPending = $shutdownTime -ne 0

# Loop for potential scheduling and rescheduling
do {
  
  if (-not $shutdownAlreadyPending -or $reschedule) {

    # Prompt the user for when (how many minutes / hours and minutes from now) to shut down.
    # Note: Pressing Ctrl-C at this prompt aborts the entire script instantly.
    while ($true) {
      try {
        $secsFromNow = switch -Regex ((Read-Host 'Enter the timespan after which to shut down, either in minutes (e.g. 30) or hours and minutes (e.g. 1:15)').Trim()) {
          '^[1-9]\d*$' { [int] $_ * 60; break }
          '^\d+:\d+$' { ([timespan] $_).TotalSeconds; break }
          default { throw }
        }
        break # input was valid; proceed below.
      }
      catch {
        Write-Warning 'Invalid timespan entered; please try again.'
      }
    }
    $shutdownTime = [datetime]::UtcNow.AddSeconds($secsFromNow)
      
    # Schedule the shutdown via shutdown.exe
    while ($true) {
      # Note: Due to use of /t with a nonzero value, /f is implied,
      #       i.e. the shutdown will be forced at the implied time.
      shutdown /s /t $secsFromNow 
      if ($LASTEXITCODE -eq 1190) {
        # A shutdown/restart is already scheduled. We cannot know for what time.
        Write-Warning "A shutdown is already pending. It will be canceled and rescheduled as reqeusted."
        shutdown /a # Abort the pending shutdown, so that the new one can be requested as scheduled.
        continue
      }
      break
    }
  
    if ($LASTEXITCODE) {
      # Unexpected error.
      Write-Error 'Scheduling the shutdown failed unexpectedly.'
      exit $LASTEXITCODE
    }
  
    # Persist the scheduled shutdown time in a file, so that
    # if this script gets killed, we can resume the countdown on re-execution.
    $shutdownTime.ToString('o') > $lastScheduleFile
  }
  
  # Show a countdown display, with support for Ctrl-C in order to cancel.
  $ctrlCPressed = $reschedule = $canceled = $false
  $prevSecsRemaining = 0
  try {
    # Make sure that [Console]::ReadKey() can read Ctrl-C as a regular keypress
    # instead of getting terminated by it.
    [Console]::TreatControlCAsInput = $true
    [Console]::CursorVisible = $false
    do {
      
      $timespanRemaining = $shutdownTime - [datetime]::UtcNow
      if ([int] $timespanRemaining.TotalSeconds -ne $prevSecsRemaining) {
        # Update only if the seconds position changed.
        Write-Host -NoNewline ("`r" + 'SHUTTING DOWN in {0:hh\:mm\:ss}, at {1}. Press Ctrl-C to CANCEL.' -f $timespanRemaining, $shutdownTime.ToLocalTime())
        $prevSecsRemaining = [int] $timespanRemaining.TotalSeconds
      }
    
      # Check for Ctrl-C
      if ([Console]::KeyAvailable) {
        # A keypress is available, consume it without displaying it.
        $key = [Console]::ReadKey($true)
        # Check if it represents Ctrl-C.
        $ctrlCPressed = $key.Modifiers -eq 'Control' -and $key.Key -eq 'C'
        if ($ctrlCPressed) {
          # Use choice.exe to prompt for further action.
          choice.exe /m "`nAre you sure you want to cancel the existing countdown to shutdown? Press N to reschedule instead, or R to resume the current countdown." /c ynr
      
          # Evaluate the user's choice, which is reflected in the exit code
          # and therefore in the automatic $LASTEXITCODE variable.
          # 1 indicates the first choice ('y'), 2 the second ('n')
          switch ($LASTEXITCODE) {
            1 {
              # YES: Cancel the shutdown and exit
              Write-Host 'Canceling shutdown.'
              $canceled = $true
              break 
            }  
            2 {
              # NO: Cancel the shutdown, but schedule a new one.
              Write-Host 'Canceling current shutdown. Please schedule a new one now:';
              $reschedule = $true
            } 
            3 {
              # RESUME: keep the current schedule and keep counting down.
            }
            Default { 
              # With three choices, this would imply a value of 0, which would signal having pressed Ctrl-C again.
              # Due to [Console]::TreatControlCAsInput = $false, however, you won't get here.
            }
          }

          if ($reschedule -or $canceled) { break }

        }
      }
    
      # Sleep only for a short while, so that checking for keyboard input is responsive.
      Start-Sleep -Milliseconds 100
    
    } while ($timespanRemaining -gt 0)
  }
  finally {
    # Clean up / restore settings.
    [Console]::CursorVisible = $true
    [Console]::TreatControlCAsInput = $false
    # Clean up the file in which the last schedule attempt is persisted. 
    # This is appropriate even if the loop is exited due to having intercepted Ctrl-C
    Remove-Item -ErrorAction Ignore $lastScheduleFile
  }

  if ($reschedule -or $canceled) {

    # Cancel the pending shutdown 
    shutdown /a *>$null
    switch ($LASTEXITCODE) {
      0 { <# OK #> }
      1116 { <# Shutdown has unexpectedly already been canceled, but that is a benign condition #> }
      default { Write-Host "`nUNEXPECTED ERROR trying to cancel the pending shutdown."; exit $_ }
    }

  }

} while ($reschedule)

# Exit the script here: either the shutdown has begun, or it has been canceled without replacement.
exit

型