Why is the Inventor add-in Application object sometimes unavailable at startup?

HANDBRAKE is one of the most popular and free video conversion tools.

It is open source, easy to use, and works on Windows and Mac.

If the fx parameter is derived from another editable parameter, you can:

• Use VBA to change the base parameter.
• The fx parameter will update automatically.

Dim oPartDoc As PartDocument
Set oPartDoc = ThisApplication.ActiveDocument

Dim oParams As Parameters
Set oParams = oPartDoc.ComponentDefinition.Parameters

oParams.Item("BaseLength").Value = 10 ' This affects fx parameters that depend on BaseLength

Yes, Nishan-it is possible to build an Inventor assembly file (.iam) offline, without launching the Inventor UI, using the ApprenticeServer API.

You can prepare a blank .iam template and use Apprentice to:

1. Open the template
2. Insert existing .ipt files as component occurrences
3. Save the modified .iam

Here’s a simplified VB.NET snippet using Apprentice:

Dim apprenticeApp As New Inventor.ApprenticeServerComponent
Dim asmDoc As ApprenticeServerDocument = apprenticeApp.Open("C:\Templates\BlankAssembly.iam")

Dim partDoc As ApprenticeServerDocument = apprenticeApp.Open("C:\Parts\MyPart.ipt")
Dim asmCompDef As ApprenticeComponentDefinition = asmDoc.ComponentDefinition

' This part is tricky — Apprentice does not expose AddOccurrence directly
' You'd need Inventor API for precise placement and constraints

asmDoc.SaveAs("C:\Assemblies\BuiltOffline.iam", False)

Here’s how to make it work more reliably:

1. Initialize Apprentice Properly

   Make sure Apprentice is initialized before loading the control:

   
   Dim appServer As Inventor.ApprenticeServerComponent = New Inventor.ApprenticeServerComponent()
           

2. Use Static Viewing Instead of Interactive Tools

   Avoid using toolbar buttons like Rotate or Zoom directly. Instead, control the view programmatically:

   
   Dim viewCtrl As InventorViewControl = Me.InventorViewControl1
   viewCtrl.ViewOrientation = Inventor.ViewOrientationEnum.kIsoTopRightView
   viewCtrl.Fit()
           

3. Disable Toolbar or Customize It

   If Rotate causes crashes, disable or hide it:

   
   viewCtrl.ToolbarVisible = False
           

   Or selectively enable safe tools:

   
   viewCtrl.ToolbarVisible = True
   viewCtrl.EnableZoom = True
   viewCtrl.EnablePan = True
   viewCtrl.EnableRotate = False ' Disable problematic tool
           

4. Use Try-Catch Around View Manipulation

   Protect your code from runtime exceptions:

   
   Try
       viewCtrl.RotateView(30, 0) ' Example: rotate 30 degrees around X
   Catch ex As Exception
       MessageBox.Show("Rotate failed: " & ex.Message)
   End Try
           

5. Ensure Graphics Compatibility

   Make sure your system supports DirectX 11 and your form has proper DPI and scaling settings. Some crashes stem from graphics context mismatches.

Use ApplicationEvents.OnSaveDocument with Filtering

You can hook into the global OnSaveDocument event and check whether the document being saved is a part, even if the save was triggered from an assembly.

VB.NET Add-In Example

Private Sub m_ApplicationEvents_OnSaveDocument( _
    ByVal DocumentObject As Inventor.Document, _
    ByVal BeforeOrAfter As Inventor.EventTimingEnum, _
    ByVal Context As Inventor.NameValueMap, _
    ByRef HandlingCode As Inventor.HandlingCodeEnum) _
    Handles m_ApplicationEvents.OnSaveDocument

    If BeforeOrAfter = EventTimingEnum.kBefore Then
        If TypeOf DocumentObject Is PartDocument Then
            ' Optional: Check if this is being saved as part of an assembly save
            ' You can compare with ActiveDocument or use Context map
            Dim partDoc As PartDocument = CType(DocumentObject, PartDocument)
            ' Run your logic here
        End If
    End If
End Sub