Retrieving session ID from COM method

I have a method named GoLogon in a COM object named BS.Logon which requires 5 parameters:

• Username
• Password
• ApplicationID
• XMLRoot
• IPAddress

This method logins to the web server with the username, password, and other details, and returns the session ID.

I have written the Powershell script to call the method GoLogon as below.

$obj=New-Object -ComObject BS.Logon
$sessionid=$obj.GoLogon([ref]$bUsername,$bPassword,$appid,$xmlroot,[ref]$ipad)
Write-Host $sessionid

When the script is executed, the method makes successful login. I can see the session ID details in the database, but I am not able to get the session ID details through script. The variable $sessionid returns null. Also the script throws exception as

Exception calling "GoLogon" with "5" argument(s): "Invalid callee. (Exception from HRESULT: 0x80020010 (DISP_E_BADCALLEE))"
At E:\Logon.ps1:18 char:1
+ $obj.Login([ref]$bUsername,$bPassword,$appid,$xmlroot,[ref]$ipad)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ComMethodTargetInvocation`

The stacktrace is:

Exception             : System.Management.Automation.MethodInvocationException: Exception calling "GoLogon" with "5" argument(s): "Invalid callee. (Exception from HRESULT: 0x80020010 (DISP_E_BADCALLEE))" ---> System.Reflection.TargetInvocationException: 
Exception has been thrown by the target of an invocation. ---> System.Runtime.InteropServices.COMException: Invalid callee. (Exception from HRESULT: 0x80020010 (DISP_E_BADCALLEE))
--- End of inner exception stack trace ---
at System.RuntimeType.InvokeDispMethod(String name, BindingFlags invokeAttr, Object target, Object[] args, Boolean[] byrefModifiers, Int32 culture, String[] namedParameters)
at System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams)
at System.Management.Automation.ComMethod.InvokeMethod(PSMethod method, Object[] arguments)
--- End of inner exception stack trace ---
at System.Management.Automation.ComMethod.InvokeMethod(PSMethod method, Object[] arguments)
at System.Management.Automation.Adapter.BaseMethodInvoke(PSMethod method, PSMethodInvocationConstraints invocationConstraints, Object[] arguments)
at System.Dynamic.UpdateDelegates.UpdateAndExecute6[T0,T1,T2,T3,T4,T5,TRet](CallSite site, T0 arg0, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5)
at System.Management.Automation.Interpreter.DynamicInstruction 7.Run(InterpretedFrame frame) at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
TargetObject          : 
CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
FullyQualifiedErrorId : ComMethodTargetInvocation
ErrorDetails          : 
InvocationInfo        : System.Management.Automation.InvocationInfo
ScriptStackTrace      : at <ScriptBlock>, E:\Logon.ps1: line 18
PipelineIterationInfo : {}
PSMessageDetails      :

Please suggest me how to get the session ID value from the method.

PowerShell seems to have a problem with COM parameters defined as VARIANT.

This is the case here, as the C++ signature of GoLogon suggests.

STDMETHODIMP CLOG::GOLogon(VARIANT *pvEmailId, BSTR bsPassword, BSTR bsIPAddress, BSTR bsSoloBuildVer, VARIANT *pvXML, BSTR *bsSessionId)

The answer suggested in this post "Invalid callee" calling a com object is to use a VariantWrapper.

In you case this should do the trick.

#define VariantWrapper for variables to be passesed as VARIANT
$wrapbUservame = New-Object Runtime.InteropServices.VariantWrapper($bUsername) 
$wrappvXML = New-Object Runtime.InteropServices.VariantWrapper($pvXML)

#pass a [ref]VariantWrapper to .COM method
$sessionid=$obj.GoLogon([ref]$wrapbUservame,$bPassword,$appid,[ref]$wrappvXML,$ipad)