Replace a Part in Nested Sub-assembly by Inventor API

By Barbara Han

Assuming you have a assembly structure as shown below:

Main Assembly
         |
        +—Part1
         |
         —-sub-assembly
                    |
                    |
                   +—Part1

Now you want to replace part1.ipt in the sub-assembly by selecting it in the browser tree and then use the Replace command to replace it with Part2.ipt. 
How can we do the replacing through code? First, you have to traverse the assembly tree and check whether an occurrence is the selected one; then get the parent occurrence of the selected occurrence, that will be the sub-assembly, then use the index to get the occurrence from the definition of the parent occurrence; finally call the ComponentOccurrence.Replace() method.

The following sample code shown below demonstrates this. To test the code you need to create a similar assembly structure.

VBA code:

Public Sub ReplacePart()
       
    ‘ Get an occurrence from the select set.
    On Error Resume Next
    Dim oOccurrence As ComponentOccurrence
    Set oOccurrence = ThisApplication.ActiveDocument.SelectSet.Item(1)
    If Err Then
        MsgBox "An occurrence must be selected."
        Err.Clear
        On Error GoTo 0
        Exit Sub
    End If

    ‘get the parent of this occurrence
    Dim oParentOcc As ComponentOccurrence
    Set oParentOcc = oOccurrence.ParentOccurrence
   
    ‘ Now get the selected occurrence in scope of parent definition
    ‘ Make sure you got parent occurrence

    If (Not oParentOcc Is Nothing) Then
        Call getOccInScopeOfSubAsmDef(oParentOcc, oOccurrence)
        If (oOccurrence Is Nothing) Then
             Exit Sub
        End If
    End If
    ‘ Now replace will work as desired
   
    On Error Resume Next
    oOccurrence.Replace "d:\temp\replacetest\part2.ipt", False
    If Err Then
        Err.Clear
        On Error GoTo 0
        MsgBox "Failed to replace component"
    End If
End Sub

Private Sub getOccInScopeOfSubAsmDef(oParentOcc As ComponentOccurrence, ByRef oOccurrence As ComponentOccurrence)
    Dim indx As Integer
    indx = 1
    Dim bFound As Boolean
    bFound = False
    Dim oOcc As ComponentOccurrence
    For Each oOcc In oParentOcc.SubOccurrences
        If oOcc Is oOccurrence Then
            bFound = True
            Exit For
        End If
        indx = indx + 1
    Next
    If (bFound) Then
        Set oOccurrence = oParentOcc.Definition.Occurrences(indx)
    Else
        Set oOccurrence = Nothing
    End If
End Sub

VB.NET code:

public static void ReplacePart()
{
    try
    {
        Inventor.Application app = (Inventor.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Inventor.Application");

        // Get an occurrence from the select set.
        ComponentOccurrence oOccurrence = app.ActiveDocument.SelectSet[1] as ComponentOccurrence;

        //get the parent of this occurrence
        ComponentOccurrence oParentOcc = oOccurrence.ParentOccurrence;

        //Now get the selected occurrence in scope of parent definition
        // Make sure you got parent occurrence
        if (oParentOcc != null)
        {
            getOccInScopeOfSubAsmDef(oParentOcc, ref oOccurrence);

        }

        if (oOccurrence != null)
        {
            oOccurrence.Replace("c:\\temp\\replacetest\\part2.ipt", false);
        }
    }
    catch
    {
    }
}
public static void getOccInScopeOfSubAsmDef(ComponentOccurrence oParentOcc, ref ComponentOccurrence oOccurrence)
{
    int indx = 1;
    bool bFound = false;

    foreach(ComponentOccurrence oOcc in oParentOcc.SubOccurrences)
    {
        if(oOcc == oOccurrence)
        {
            bFound = true;
            break;
        }

        indx = indx + 1;
    }

    if (bFound)
    {
        oOccurrence = o
ParentOcc.Definition.Occurrences[indx];
    }
    else
    {
        oOccurrence = null;
    }
}