PowerShell 技能连载 - 验证变量有效性

变量和函数参数可以通过验证属性自动地验证有效性。以下是一个简单的例子,确保 $test1 只能存储 1-10 之间的值:

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[ValidateRange(1,10)]$test1 = 10

当您将一个小于 1 或大于 10 的值赋给这个变量,PowerShell 将会抛出一个异常。不过通过这种方式您无法控制异常的问本。

通过使用脚本验证器,您可以选择自己希望的错误信息:

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[ValidateScript({
If ($_ -gt 10)
{ throw 'You have submitted a value greater than 10. That will not work, dummy!' }
Elseif ($_ -lt 1)
{ throw 'You have submitted a value lower than 1. That will not work, dummy!' }

$true
})]$test2 = 10

以下是输出结果:

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PS C:\> $test2 =  4

PS C:\> $test2 = 11
You have submitted a value greater than 10. That will not work, dummy!
At line:5 char:3
+ { throw 'You have submitted a value greater than 10. That will not work, dummy ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OperationStopped: (You have submitted a...not work, dummy!:String
) [], RuntimeException
+ FullyQualifiedErrorId : You have submitted a value greater than 10. That will not work, dummy!



PS C:\> $test2 = -2
You have submitted a value lower than 1. That will not work, dummy!
At line:7 char:3
+ { throw 'You have submitted a value lower than 1. That will not work, dummy ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OperationStopped: (You have submitted a...not work, dummy!:String
) [], RuntimeException
+ FullyQualifiedErrorId : You have submitted a value lower than 1. That will not work, dummy!

本文国际来源:Validating Variables

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