VB.NET set CommandInProgress fails

Hi,

I tried to use CommandInProgress property, but I have issues with it.

2010 SOLIDWORKS API Help - CommandInProgress Property (ISldWorks)

I'd like to set this property to True before my app begins to work, and like to set to False when it ends, like the link said above.

I have this Modules /Classes:

Public Class MainForm

    Public Sub MainForm_Load... 'This runs first

SwxConnectModule.SwxConnect()

...

Public Module SwxConnectModule

Public swApp As SldWorks.SldWorks

....

Public Class myForm

Public Sub myForm_Load...

...

Public Sub myForm_FormClosed...

...

I tried this many ways seen below, but seems I couldn't set this property.

Method 1

Public Module SwxConnectModule

Public swApp As SldWorks.SldWorks

....

Public Class myForm

...

Public Sub myForm_FormClosed..

swApp.CommandInProgress = False

Debug.Print(swApp.CommandInProgress) '--This prints True

...

Method 2

Public Module SwxConnectModule

Public swApp As SldWorks.SldWorks

Public swIApp As SldWorks.ISldWorks '--ISldworks Interface

....

Public Class myForm

...

Public Sub myForm_FormClosed...

swIApp.CommandInProgress = False '--This occurs: Exception thrown: 'System.NullReferenceException' in SWXapp.exe

Debug.Print(swApp.CommandInProgress)

...

Method 3

Public Module SwxConnectModule

Public swApp As SldWorks.SldWorks

....

Public Class myForm

    Public swIApp As SldWorks.ISldWorks '--ISldworks Interface inside myForm Class

...

Public Sub myForm_FormClosed...

swIApp.CommandInProgress = False '--This occurs: Exception thrown: 'System.NullReferenceException' in SWXapp.exe

Debug.Print(swApp.CommandInProgress)

...

Method 4

Public Module SwxConnectModule

Public swApp As SldWorks.SldWorks

....

Public Class myForm

   

...

Public Sub myForm_FormClosed...

   Dim swIApp As SldWorks.ISldWorks '--ISldworks Interface inside closing Sub

swIApp.CommandInProgress = False '--This occurs: Exception thrown: 'System.NullReferenceException' in SWXapp.exe

Debug.Print(swApp.CommandInProgress)

...

Anybody has any idea?

Thank you

SolidworksApi macros