Question

我想编写一个脚本，提示用户输入以分钟为单位的时间来启动关闭计时器。我可以使用它，但是没有输入验证。这就是我所拥有的。

DO{
try{

$numOk= $true
[int] $minutes= Read-Host "Enter the amount in minutes until a shut down (0 to cancel)"
#$minutes= [int]$minutes

}
catch{

#if($minutes -isnot [int]){}
$numOk= $false
Write-Host "Input is not an integer!!!!!"
}

} while ($numOk = $false)


[int] $seconds= $minutes*60

if($seconds -eq 0){
shutdown -a
}
else{
shutdown -s -t $seconds
}

输入字母时我得到一个非常奇怪的值。

PS C:\Users\USER\Desktop\shut down> .\shutdownTimer.ps1
Enter the amount in minutes until a shut down (0 to cancel): a
Input is not an integer!!!!!
Cannot convert value "555555555555555555555555555555555555555555555555555555555555" to type "System.Int32". Error: "Value was either 
too large or too small for an Int32."
At C:\Users\USER\Desktop\shut down\shutdownTimer.ps1:25 char:1
+ [int] $seconds= $minutes*60
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvalidCastFromStringToInteger

shutdown : Unable to abort the system shutdown because no shutdown was in progress.(1116)
At C:\Users\USER\Desktop\shut down\shutdownTimer.ps1:29 char:1
+ shutdown -a
+ ~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (Unable to abort...progress.(1116):String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

不太确定所有这五个数字来自何处。

Answer 1

您的代码在while ($numOk = $false)处出错。在powershell中，=是赋值运算符。比较运算符是shell样式的：-eq，-ne，-gt，-gte，-lt，-lte，-like等。请参见here

您可能想使用[int]::TryParse测试输入，如下所示：

$inputValue = 0
do {
    $inputValid = [int]::TryParse((Read-Host 'gimme a number'), [ref]$inputValue)
    if (-not $inputValid) {
        Write-Host "your input was not an integer..."
    }
} while (-not $inputValid)

Answer 2

如果将变量强制转换为int，PowerShell将自动检查输入。无法将a分配给$minutes，因为不能将其转换为int。我确定您的变量已在您的PowerShell会话中以a的形式分配给string。 'a' * '60'是a的60倍，这会产生错误。清理变量，更好地重写代码。不需要Read-Host和所有输入验证。 PowerShell将为您完成所有这些工作。

param(
    # Enter the amount in minutes until a shut down
    [int]$Minutes = 1
)
$Seconds = $Minutes * 60
Start-Sleep -Seconds $Seconds
Stop-Computer

Powershell输入验证整数

2 个答案: