Unable to Run [System.__ComObject].InvokeMember within PowerShell Function - powershell

I've been trying to write a program to access properties and methods of a 3rd party OLE DLL.
Below code runs fine.
[System.__ComObject].InvokeMember("AppName", [System.Reflection.BindingFlags]::GetProperty, $null, $appObj, $null)
As the invocation is going to be repetitive, I want to call a wrapper like below.
function Get-Property {
param(
$objOLE,
[String] $propertyName
)
[System.__ComObject].InvokeMember($propertyName,[System.Reflection.BindingFlags]::GetProperty,$null,$objOLE,$null)
}
When the script runs
Get-Property($appObj, "AppName")
I got this error:
Exception calling "InvokeMember" with "5" argument(s): "Method 'System.__ComObject.ToString' not found."
At F:\Scripts\test.ps1:21 char:36
+ [System.__ComObject].InvokeMember <<<< ($propertyName,[System.Reflection.BindingFlags]::GetProperty,$null,$objOLE,$null)
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
This is confusing. Anybody has an insight? Thank you in advance.

Remember your function is a PowerShell function/command and not a .NET method i.e. don't use parens and don't comma separate args:
Get-Property $appObj AppName
The way you had it, your function gets one argument that is an array with two elements.

Related

$Var.ToUpper() throwing "You cannot call a method on a null-valued expression."

Everyone.
I'm not sure why this is happening, but in my PowerShell script I am converting a string (server name entered by the end user) to uppercase. My trouble is that when I run my script it throws the error "You cannot call a method on a null-valued expression." on the open/close parentheses of the *.ToUpper(). As far as I know using ToUpper it in this case should just shift the case.
Here's an example:
$Server = $Server.ToUpper()
And the output:
You cannot call a method on a null-valued expression.
At C:\TEMP\Servers.ps1:705 char:2
+ $Server = $Server.ToUpper()
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
Now, I have tried to just convert to uppercase on whatever action I am calling, for instance:
$GP = Get-printer -ComputerName $Server.ToUpper()
The above also fails on the "()".
But it doesn't seem to be happening all the time. I am converting in numerous places and it's working as expected, but sporadically in the script it's throwing errors.
I've tried $Server = $Server.ToUpper() and $Server = $Server.ToUpper -- and I get mixed results of success and errors.
I'm betting I'm missing something small with this. Any advice on how to resolve?
Thanks,
Dale

ExecutionContext.InvokeCommand.ExpandString throws exception in PowerShell 4.0

I have a script as below
[string]$newValue = Get-ConfigurationByType $setting.Value
After this line, the value of $newValue is
"http://ST-$($partner.Alias).vardiaforsakring.se/CardPaymentAgreementCallback.aspx"
In the loop, I call ExpandString
foreach ($partner in $partners)
{
$partnerSpecificValue =$ExecutionContext.InvokeCommand.ExpandString($newValue)
}
It throws exception
Exception calling "ExpandString" with "1" argument(s): "Object reference not set to an instance of an object."
At C:\Programs\Drops\Hydra_SE_v1.28\HydraDeploymentFunctions.ps1:342 char:5
+ $partnerSpecificValue = $ExecutionContext.InvokeCommand.ExpandString($newVal ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : NullReferenceException
But when I try to input hard-code string, it returns expected result without exception
$partnerSpecificValue =$ExecutionContext.InvokeCommand.ExpandString("http://ST-$($partner.Alias).vardiaforsakring.se/CardPaymentAgreementCallback.aspx")
The value of $partnerSpecificValue is
http://ST-secure.vardiaforsakring.se/CardPaymentAgreementCallback.aspx
Does anyone know a workaround to resolve this bug? Thank you very much. I am running PowerShell v4.0 on Windows Server 2012 R2.
ExpandString is problematic and doesn't work correctly in general case. I use this method instead:
function render() {
[CmdletBinding()]
param ( [parameter(ValueFromPipeline = $true)] [string] $str)
"#`"`n$str`n`"#" | iex
}
Example:
$x=#{test='test'}
'Hashtable x contains value $($x.test)' | render
I have a workaround for this bug.
https://social.technet.microsoft.com/Forums/en-US/5efc52d2-619c-4063-9a47-bc646c45e882/executioncontextinvokecommandexpandstring-throws-exception-in-powershell-40?forum=winserverpowershell

How to pass a custom enum to a function in powershell

When defining a function, how can you reference a custom enum?
Here's what I'm trying:
Add-Type -TypeDefinition #"
namespace JB
{
public enum InternetZones
{
Computer
,LocalIntranet
,TrustedSites
,Internet
,RestrictedSites
}
}
"# -Language CSharpVersion3
function Get-InternetZoneLogonMode
{
[CmdletBinding()]
param
(
[Parameter(Mandatory=$true)]
[JB.InterfaceZones]$zone
)
[string]$regpath = ("HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\{0}" -f [int]$zone)
$regpath
#...
#Get-PropertyValue
}
Get-InternetZoneLogonMode -zone [JB.InternetZones]::TrustedSites
But this gives the error:
Get-ZoneLogonMode : Unable to find type [JB.InterfaceZones]. Make sure that the assembly that contains this type is loaded.
At line:29 char:1
+ Get-ZoneLogonMode -zone [JB.InternetZones]::TrustedSites
+ ~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (JB.InterfaceZones:TypeName) [], RuntimeException
+ FullyQualifiedErrorId : TypeNotFound
NB: I'm aware I could use ValidateSet for similar functionality; however that has the disadvantage of only having a name value; as opposed to allowing me to program using friendly names which are then mapped to ints in the background (I could write code for that; but enum seems more appropriate if possible).
I'm using Powershell v4, but ideally I'd like a PowerShell v2 compatible solution as most users are on that version by default.
Update
I've corrected the typo (thanks PetSerAl; well spotted).
[JB.InterfaceZones]$zone now changed to [JB.InternetZones]$zone.
Now I'm seeing error:
Get-InternetZoneLogonMode : Cannot process argument transformation on parameter 'zone'. Cannot convert value "[JB.InternetZones]::TrustedSites" to type
"JB.InternetZones". Error: "Unable to match the identifier name [JB.InternetZones]::TrustedSites to a valid enumerator name. Specify one of the following
enumerator names and try again: Computer, LocalIntranet, TrustedSites, Internet, RestrictedSites"
At line:80 char:33
+ Get-InternetZoneLogonMode -zone [JB.InternetZones]::TrustedSites
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Get-InternetZoneLogonMode], ParameterBindingArgumentTransformationException
+ FullyQualifiedErrorId : ParameterArgumentTransformationError,Get-InternetZoneLogonMode
The ISE gave this one away to me but your attempted syntax was not completely incorrect. I was able to do this and get it to work.
Get-InternetZoneLogonMode -Zone ([JB.InternetZones]::TrustedSites)
Again, If you look at the highlighting you will see how I came to that conclusion.
Per comments by PetSerAl & CB:
Corrected typo in function definition
from [JB.InterfaceZones]$zone
to [JB.InternetZones]$zone
Changed function call
from Get-InternetZoneLogonMode -zone [JB.InternetZones]::TrustedSites
to Get-InternetZoneLogonMode -zone TrustedSites

Psake Include method not working

I am writing a simple PS script with Psake and I have a problem when I try to include another ps1 file.
PS C:\CI> Include .\EnvSettings.ps1
I have this exception
Exception calling "Peek" with "0" argument(s): "Stack empty."
At C:\Users\Julien\Documents\WindowsPowerShell\Modules\psake\psake.psm1:227 char:2
+ $psake.context.Peek().includes.Enqueue(($pa));
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : InvalidOperationException
I had a look at psake.psm1 line 227 to see what's going on around
# .ExternalHelp psake.psm1-help.xml
function Include {
[CmdletBinding()]
param(
[Parameter(Position=0,Mandatory=1)][string]$fileNamePathToInclude
)
Assert (test-path $fileNamePathToInclude -pathType Leaf) ($msgs.error_invalid_include_path -f $fileNamePathToInclude)
$psake.context.Peek().includes.Enqueue((Resolve-Path $fileNamePathToInclude));
}
The code succesfully pass the Assert line.
The problem comes from the Resolve-Path $fileNamePathToInclude, it returns nothing...
If I try it from the command line it works fine.
Anyone experienced this problem before?
The way to include a file is not Include .\EnvSettings.ps1 , but just "dot source" the file :
. .\EnvSettings.ps1

Calling [ADSI] with external parameter

I am not very familiar with powershell scripting and I'm stuck on this problem -
I need to make some operations on object retrieved like this:
$object = [ADSI]'LDAP://CN=Test User,OU=Dept,OU=Users,DC=example,DC=org'
...
$object.Commit()
this works fine, but I have to use distinguished name stored in variable - my test script looks like this, but its not working:
$object = [ADSI]'LDAP://$variable'
...
$object.Commit()
the first call to [ADSI] itself doesn't cause error, but any following operation crashes with message:
The following exception occurred while retrieving member "commit": "The server is not operational.
"
At line:1 char:10
+ $object.commit <<<< ()
+ CategoryInfo : NotSpecified: (:) [], ExtendedTypeSystemException
+ FullyQualifiedErrorId : CatchFromBaseGetMember
I'm pretty sure, that the parameter is sent in some wrong way, but I don't know, how to fix it, can anybody help?
tahnks
Try:
$object = [ADSI]"LDAP://$variable"
Single quotes don't expand variables.