Checking if a string is NULL or EMPTY is very common requirement in Powershell script. If we don’t do that we will end up with run time errors if we try to perform some operation on that string variable which i
PS>$null-eq$undefinedVariableTrue 如果碰巧错误键入变量名称,PowerShell 会将它视为不同的变量,并且值为$null。 找到$null值的另一种方法是,当它们来自未提供任何结果的其他命令时。 PowerShell PS>functionGet-Nothing{} PS>$value=Get-NothingPS>$null-eq$valueTrue ...
function Test-MrParameterValidation { [CmdletBinding()] param ( [ValidateNotNullOrEmpty()] [string[]]$ComputerName = $env:COMPUTERNAME ) Write-Output $ComputerName } 详细输出 如果要编写复杂的代码,则内联注释非常有用,但除非用户查看代码,否则不会看到它们。 以下示例中的函数在 foreach 循环内有一...
ValidateSetAttribute:限制变量的取值集合 ValidateNotNullAttribute 例子 ValidateNotNullOrEmptyAttribute 例子,注意@()为一个空数组。
特性的值HelpMessage不应为空字符串或 null 值,因为这会导致 PowerShell 解释器在执行函数或 cmdlet 时引发错误。 方式 指定HelpMessage属性的值。 示例 错 PowerShell FunctionBadFuncEmptyHelpMessageEmpty {Param( [Parameter(HelpMessage='')] [String]$Param)$Param}FunctionBadFuncEmptyHelpMessage...
Indicates if this PowerShell object is the owner of the runspace or RunspacePool assigned to this object. Runspace Sets an associated Runspace for this PowerShell instance. This can be null in which case a new runspace is created whenever Invoke* method is called. RunspacePool Sets an assoc...
Indicates if this PowerShell object is the owner of the runspace or RunspacePool assigned to this object. Runspace Sets an associated Runspace for this PowerShell instance. This can be null in which case a new runspace is created whenever Invoke* method is called. RunspacePool Sets an ...
function Get-FunctionPosition { [CmdletBinding()] [OutputType('FunctionPosition')] param( [Parameter(Position = 0, Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName)] [ValidateNotNullOrEmpty()] [Alias('PSPath')] [System.String[]] $Path ) process { try { $filesToProcess = if (...
I disagree. Allowing[NullString]::Valueto propagate without conversion to[string]::emptyis useful when optional string parameters are handled in bulk using eitherValueFromPipelineByPropertyNameor via hashtable splatting. Here is an example using the former demonstrating parameter passing that arises na...
Workaround for NullReferenceException when extracting multiple 7zip archives simultaneously on PS 7.4.0 (contributed by @kborowinski in #89) Adds new parameter EncryptionMethod to Compress-7Zip Updates of 7-Zip libraries to version 24.06 (support for ZSTD decompression ) (contributed by @kbo...