如何在 PowerShell 函数中使用 ValidateSet 属性?
PowerShell 函数中的 ValidateSet 属性用于验证从集合中输入的值,这意味着它只允许从集合中获取特定值。为更好的理解,请考虑下面的示例,我们有一个数组,我们需要检查输入的值是否在数组中,如果是,我们将使用以下代码。
Function PetAnimalsCheck {
param(
[String]$Animal
)
$Animals = "Cow","Dog","Cat","Horse","Camel","Elephant"
if($Animals -contains $Animal) {
Write-Output "Animal is in the list of Pet Animals"
} else {
Write-Output "Animal is not Pet Animal"
}
}输出
PS C:\> PetAnimalsCheck -Animal Dog Animal is in the list of Pet Animals PS C:\> PetAnimalsCheck -Animal Tiger Animal is not Pet Animal
如果我们使用 ValidateSet 属性替换上述命令,代码将只有几行。
Function PetAnimalsCheck {
param(
[ValidateSet("Cow","Dog","Cat","Horse","Camel","Elephant",ErrorMessage="Ani
mal Name is not among list")]
[String]$Animal
)
Write-Output "Animal is Pet Animal"
}输出
PS C:\> PetAnimalsCheck -Animal Tiger PetAnimalsCheck: Cannot validate argument on parameter 'Animal'. Animal Name is not among list PS C:\> PetAnimalsCheck -Animal Cat Animal is Pet Animal
如果您需要集合区分大小写,请使用 IgnoreCase 值。
Function PetAnimalsCheck {
param(
[ValidatepathExi]
[ValidateSet("Cow","Dog","Cat","Horse","Camel","Elephant",ErrorMessage="Ani
mal Name is not among list or case sensitive", IgnoreCase=$false)]
[String]$Animal
)
Write-Output "Animal is Pet Animal"
}输出
PS C:\> PetAnimalsCheck -Animal cat PetAnimalsCheck: Cannot validate argument on parameter 'Animal'. Animal Name is not among list or case sensitive PS C:\> PetAnimalsCheck -Animal Cat Animal is Pet Animal
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