通过反射获取cmdlet的动态参数

Question

Powershell基于上下文暴露了一些参数“dynamic parameters”。 MSDN页面很好地解释了这种机制，但最重要的是要找出这些必须调用GetDynamicParameters()，它返回一个包含附加参数的类。我需要通过反射来获取这些参数，并且（这里是关键所在），在ReflectionOnly上下文中（也就是说，类型使用ReflectionOnlyLoadFrom加载）。所以，没有Assembly.InvokeMember（“GetDynamicParameters”）。

可以这样做吗？

Answer 1

编号反射对静态汇编元数据有效。 PowerSHELL中的动态参数通过命令或函数本身在运行时上添加。

Answer 2

也许这有助于：

1：动态参数的确定指标

#=================================================================================== 
# DEFINITION OF FREE FIELDS USED BY THE CUSTOMER 
#----------------------------------------------------------------------------------- 
# SYNTAX: @{ <FF-Name>=@(<FF-Number>,<isMandatory_CREATE>,<isMandatory_UPDATE>); } 
$usedFFs = @{    
         "defaultSMTP"=@(2,1,0); ` 
         "allowedSMTP"=@(3,1,0); ` 
         "secondName"=@(100,1,0); ` 
          "orgID"=@(30001,1,0); ` 
      "allowedSubjectTypeIDs"=@(30002,1,0); ` 
      } 

# FF-HelpMessage for input   
$usedFFs_HelpMSG = @{ 2="the default smtp domain used by the organizaiton. Sampel:'algacom.ch'"; ` 
         3="comma seperated list of allowed smtp domains. Sampel:'algacom.ch,basel.algacom.ch'"; ` 
         100="an additional organization name. Sampel:'algaCom AG')"; ` 
         30001="an unique ID (integer) identifying the organization entry"; ` 
         30002="comma seperated list of allowed subject types. Sampel:'1,2,1003,10040'"; ` 
      } 

2：函数定义，建立动态参数

#-------------------------------------------------------------------------------------------------------   
# Build-DynParams : Used to build the dynamic input parameters based on $usedFFs/$usedFFs_HelpMSG 
#------------------------------------------------------------------------------------------------------- 
function Build-DynParams($type) { 
    $paramDictionary = New-Object -Type System.Management.Automation.RuntimeDefinedParameterDictionary 

    foreach($ffName in $usedFFs.Keys) { 
     $ffID = $usedFFs.Item($ffName)[0] 
     $dynAttribCol = New-Object -Type System.Collections.ObjectModel.Collection[System.Attribute] 
     $dynAttrib = New-Object System.Management.Automation.ParameterAttribute 
     $dynAttrib.ParameterSetName = "__AllParameterSets" 
     $dynAttrib.HelpMessage = $usedFFs_HelpMSG.Item($ffID) 
     switch($type) { 
      "CREATE" { $dynAttrib.Mandatory = [bool]($usedFFs.Item($ffName)[1]) } 
      "UPDATE" { $dynAttrib.Mandatory = [bool]($usedFFs.Item($ffName)[2]) } 
     } 
     $dynAttribCol.Add($dynAttrib) 
     $dynParam = New-Object -Type System.Management.Automation.RuntimeDefinedParameter($ffName, [string], $dynAttribCol) 
     $paramDictionary.Add($ffName, $dynParam)   
    } 
    return $paramDictionary   
} 

3.功能，使得使用的动态参数

#------------------------------------------------------------------------------------------------------- 
# aAPS-OrganizationAdd : This will add a new organization entry 
#------------------------------------------------------------------------------------------------------- 
Function aAPS-OrganizationAdd { 
    [CmdletBinding()] 
    Param(
     [Parameter(Mandatory=$true,HelpMessage="The name of the new organization")] 
     [String]$Descr, 
     [Parameter(Mandatory=$false,HelpMessage="The name of the parent organization")] 
     [String]$ParentDescr=$null, 
     [Parameter(Mandatory=$false,HelpMessage="The status of the new organization [1=Active|2=Inactive]")] 
     [int]$Status = 1, 
     [Parameter(Mandatory=$false,HelpMessage="If you want to see the data of the deactivated object")] 
     [switch]$ShowResult 
    ) 
    DynamicParam { Build-DynParams "CREATE" } 

    Begin {} 

    Process { 
     # do what oyu want here 
    } 

    End {} 
}