Using Xaml WorkFlow In Another Xaml workflow in Rehosted Designer

Question

I'm writing a workflow WPF Designer Re hosting Application and I want to use An Xaml Inside Another One(Like Sub Workflow) I make workflow file with sub workflow In Vs 2013 workflow Designer but in my Re hosting Application It's not working Actually The Application Couldn't Recognize it.

I also loaded my Xaml Sub workflow file in an activity in this way:

Activity workflow1 = ActivityXamlServices.Load(ActivityXamlServices.CreateReader(new    XamlXmlReader(@"C:\insideworkflow.xaml", new XamlXmlReaderSettings { LocalAssembly = System.Reflection.Assembly.GetExecutingAssembly() })));

and I want to know how should I load it to designer which the designer could recognize it also I want to use sub workflow in toolbox and reuse it how can I make it reusable.