Pass the Application object to a VB Form

Summary

When developing a VB ActiveX DLL project that contains a Form, the Form needs to know about ArcMap. In that case, it is required to pass an Application object to the Form.

Procedure

1. Create a new Visual Basic ActiveX .DLL project that implements ICommand.
   <a href='http://support.esri.com/en/knowledgebase/techarticles/detail/23923' target='_blank'>How To: Implement ICommand in Visual Basic</a>
2. Add a Form to the project and name the Form frmApp.
3. In the General Declarations section of the frmApp code module, declare a module-level reference to the Application.
   
   

   Code:
   Option Explicit
   Private m_pApp As IApplication
   

   
   
4. In frmApp, add Public Get and Set properties for the Application.
   
   

   Code:
   Public Property Set Application(pApp As IApplication)
   
       Set m_pApp = pApp
       ' *************************
       ' Add your custom code here
       ' *************************
   End Property
   
   Public Property Get Application() As IApplication
       Set Application = m_pApp
   End Property
   

   
   
5. In the Class Module clsApp, rewrite the implementation code for the OnCreate method of ICommand:
   
   

   Code:
   Private Sub ICommand_OnCreate(ByVal hook As Object)
   
          Set frmApp.Application = hook
   
   End Sub
   

   
   
6. In Class_Terminate of clsApp, remember to release the reference to the application.
   
   

   Code:
   
   Private Sub Class_Terminate()
       Set frmApp.Application = Nothing
       Unload frmApp
   End Sub