Cannot bind argument to parameter 'Password' because it is null. Cannot bind argument to parameter 'Path' because it is null Cannot bind argument to parameter 'Path' because it is null in ISE Cannot bind argument to parameter xxxxx' because it is an empty string. Cannot bind parameter 'Date...
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 is empty or null. So the question now is, how to check it? Well, belo...
$null是 PowerShell 中用于表示 NULL 的自动变量。 可以将其分配给变量,在比较中使用,并将它用作集合中 NULL 值的占位符。 PowerShell 将$null视为具有 NULL 值的对象。 如果你使用其他语言,则这会与你的预期不同。 $null 示例 任何时候尝试使用尚未初始化的变量时,值都为$null。 这是$null值混入代码的最...
functionTest-MrParameterValidation{ [CmdletBinding()]param( [ValidateNotNullOrEmpty()] [string[]]$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。
如果需要指定一个默认参数需要将ValidateNotNullOrEmpty参数验证属性与默认值一起使用,不过不能与必需(Mandatory)参数一起使用! functionTest-MrParameterValidation { [CmdletBinding()]param( [ValidateNotNullOrEmpty()] [string[]]$ComputerNmae="s1")
特性的值HelpMessage不应为空字符串或 null 值,因为这会导致 PowerShell 解释器在执行函数或 cmdlet 时引发错误。 方式 指定HelpMessage属性的值。 示例 错 PowerShell FunctionBadFuncEmptyHelpMessageEmpty {Param( [Parameter(HelpMessage='')] [String]$Param)$Param}FunctionBadFuncEmptyHelpMessage...
[ValidateNotNull] [ValidateNotNullOrEmpty] [ValidateNotNullOrWhiteSpace] [ValidatePattern] [ValidateRange] [ValidateScript] [ValidateSet] [ValidateTrustedData] [ValidateUserDrive] [version] [void] [WildcardPattern] [wmi] [wmiclass] [wmisearcher] [X500DistinguishedName] [X509Certificate] [xml] Only...
Calling the function at the beginning, or outside of a pipeline, executes theprocessblock once. Within a pipeline, theprocessblock executes once for each input object that reaches the function. If the pipeline input that reaches the function is empty, theprocessblockdoes notexecute. ...
IsArray IsBoolean IsDateTime IsInteger IsLower IsNumeric IsString IsUpper JsonSchema Less LessOrEqual Like Match NotContains NotCount NotEndsWith NotHasField NotIn NotLike NotMatch NotNull NotStartsWith NotWithinPath Null NullOrEmpty TypeOf
and 1 elementsArgument type ServiceController is not IList, treating this as scalarAdding scalar element of type ServiceController to array position 0Ok, we're almost finished with binding, but first we'll validate that the parameter is not null or empty. This is necessary...