iLogic Rule Object reference not set to an instance of an object

[timothy_berg]

Hello, I am working on a rule that will rename the sheet name in the browser for easier exporting to DWG. The code below works on some drawings and some drawings it does not work, not sure what i have wrong. The error i get is "Object reference not set to an instance of an object." not sure what this means please help.

SyntaxEditor Code Snippet

Dim oSheets As Sheets = ThisDrawing.Document.sheets
Dim oSheet As Sheet


For Each oSheet In oSheets
    oSheet.activate
    Dim oDrawingView As DrawingView = oSheet.DrawingViews(1)
    oModel = ActiveSheet.View(oDrawingView.Name).ModelDocument
    EquipName = iProperties.Value(oModel.DisplayName, "Summary", "Comments")
    EquipName1=Left(EquipName,3)
    'MessageBox.Show(EquipName1)
    

    ActiveSheet.Sheet.Name = iProperties.Value("Custom", "EQUIP_CAT") &"-"& iProperties.Value("Custom", "DWG_EQUIP_NAME") & "-" & iProperties.Value("Custom", "DERIVATIVE") & "-" & EquipName1
Next

[MechMachineMan]

in the rule environment, you can do a manual debug by coding in the line

MsgBox("Here")

and starting at the top then moving it down to see where/what line your code fails at.

[timothy_berg]

did that and this is what popped up    

also this is the text that is on the more info tab of the error message

System.NullReferenceException: Object reference not set to an instance of an object.
at iLogic.CadAssemblyUtil.FindComponentOccurrence(Document rootDoc, Object compoName, Boolean topLevelOnly, Boolean inTopLevelContext)
at iLogic.CadCompoOrDoc..ctor(Document rootDoc, Object oName)
at iLogic.CadPropertiesInRule.FindCompoOrDoc(Object compoOrDocName)
at iLogic.CadPropertiesInRule.InvPropertyInCompoOrDoc(Object compoOrDocName, String setName, String propName, Boolean createCustom)
at iLogic.CadPropertiesInRule.get_Value(Object compoOrDocName, String setName, String propName)
at LmiRuleScript.Main()
at Autodesk.iLogic.Exec.AppDomExec.ExecRuleInAssembly(Assembly assem)
at iLogic.RuleEvalContainer.ExecRuleEval(String execRule)

[MechMachineMan]

But at what line? If you put it as the first line in the code does it run
and pop up the window?

[timothy_berg · Accepted solution]

SyntaxEditor Code Snippet

Dim oSheets As Sheets = ThisDrawing.Document.sheets
Dim oSheet As Sheet


For Each oSheet In oSheets
    oSheet.activate
    Dim oDrawingView As DrawingView = oSheet.DrawingViews(1)
    oModel = ActiveSheet.View(oDrawingView.Name).ModelDocument
    
    EquipName = iProperties.Value(oModel.DisplayName, "Summary", "Comments")
    MsgBox("Here")
    EquipName1=Left(EquipName,3)
    'MessageBox.Show(EquipName1)
    
    
    

    ActiveSheet.Sheet.Name = iProperties.Value("Custom", "EQUIP_CAT") &"-"& iProperties.Value("Custom", "DWG_EQUIP_NAME") & "-" & iProperties.Value("Custom", "DERIVATIVE") & "-" & EquipName1
Next

with the MsgBox in that location i get the error before the message

[MechMachineMan]

So it's telling you it doesn't like the line that you access the iproperty on.

Other ways to write this line would be like:

EquipName = oModel.PropertySets("Inventor Summary Information")("Comments").Value

and to find out what is the proper descriptors, use:

http://modthemachine.typepad.com/my_weblog/2010/02/accessing-iproperties.html

Note: the above code is actually a shortened versions due to the default property of the calls being its Item. The shorthand says that you can replace the ".Item" (or other default property/method) with the brackets that outline the default property/method arguements.

The line, without the shorthand would be:

EquipName = oModel.PropertySets.Item("Inventor Summary Information").Item("Comments").Value

[timothy_berg]

that worked! thanks for the help

Do you have time for one more tweek? Is there a way to run the code on certain sheets only, for example 1-6 and ignore the remainder?

[MechMachineMan]

Programmatically yes, just need to come up with a criteria to test on for
each sheet to tell it whether to run for that sheet or not

[timothy_berg · Accepted solution]

Got it to work with an If and Then statement thanks for the help

[Anonymous]

Where did/would one place the ' If ' & ' Then ' words in the code? ? ? 

[bradeneuropeArthur]

if sheet.item(1) then

end if

if sheet.item(2) then

end if

'till

if sheet.item(6) then

end if

I think!