Problem in creation of Detail Line

[MehtaRajesh]

Hello All, 

I am creating Detail Line in View, I am getting error "System.NullReferenceException: Object reference not set to an instance of an object"  at DetailLine line1 = doc.Create.NewDetailCurve(view, geomLine1) as DetailLine; 

Please let me know why this error is coming and what is the solution,
Thanks in advance for your kind support in this regards
Rajesh

ExternalCommandData cdata = commandData;
m_app = commandData.Application;
m_doc = commandData.Application.ActiveUIDocument.Document;               
view = m_doc.ActiveView;
uiApp = commandData.Application;
uiDoc = uiApp.ActiveUIDocument;   
app = m_app.Application; 

if (null == m_doc)
{
   message = "There is no active document.";
   return Autodesk.Revit.UI.Result.Failed;
}

// Create a few geometry lines. These lines are transaction (not in the model),
// therefore they do not need to be created inside a document transaction.
XYZ Point1 = XYZ.Zero;
XYZ Point2 = new XYZ(10, 0, 0);
XYZ Point3 = new XYZ(10, 10, 0);
XYZ Point4 = new XYZ(0, 10, 0);

Line geomLine1 = Line.CreateBound(Point1, Point2);              

// This geometry plane is also transaction and does not need a transaction
XYZ origin = XYZ.Zero;
XYZ normal = new XYZ(0, 0, 1);
Plane geomPlane = app.Create.NewPlane(normal, origin);
using (Transaction transaction = new Transaction(m_doc))
{
   if (transaction.Start("Create model curves") == TransactionStatus.Started)
   {
      // Create a sketch plane in current document
      SketchPlane sketch = SketchPlane.Create(m_doc, geomPlane);                

      DetailLine line1 = doc.Create.NewDetailCurve(view, geomLine1) as DetailLine; 
	(ERROR I am getting is System.NullReferenceException: Object reference not set to an instance 	of an object
   }

}

[Anonymous]

Hello MehtaRajesh,

are you running it in a view where detail lines can't be created?

Where do you start/Commit your transaction?

/Martin

[MehtaRajesh]

Hi Martin,

Thanks,

I need to create Detail Line in currently opened Sheet,
Please help me, what I am doing wrong in the code.

Thanks and Regards,
Rajesh

[Anonymous · Accepted solution]

When creating your detail line you are using doc.create but your Document variable is named m_doc

Change your transaction to something like this:

Transaction transaction = new Transaction(m_doc, "Create Detail Line");
{
 transaction.Start();
      // Create a sketch plane in current document
      SketchPlane sketch = SketchPlane.Create(m_doc, geomPlane);                

      DetailLine line1 = m_doc.Create.NewDetailCurve(view, geomLine1) as DetailLine; 
	

 transaction.Commit();
}
   }

Good Luck!

 /Martin