In my custom control I am parsing sub properties between my controls tags. 
The elements in between the tags should form a collection property but will 
also contain controls themselves. In this scenario I am slightly confused as 
it appears you should use ParseChildren(true, "<defaultproperty>") when the 
inner content is to be parsed as properties or PersistChildren(true) when the 
inner content is to be parsed as controls. What if you want both conditions?

One way I have implemented this is to parse the inner contents using 
ParseChildren(true) and then to override CreateChildControls method and add 
the inner controls through the property collection to the control tree. When 
using ParseChildren(true) the method AddParseSubObject does not fire and 
therefore how should I inspect the contents between my tags when they are 
parsed so that I can test declarative attributes and raise exceptions if 
required. Should I be looking to override the ControlBuilder class?

Any help would be much appreciated.