Fri, 08/30/2002 - 09:38
Forums:
Hi,
How can I create object using the type information. In MFC, if you declare a class use the DECLARE_DYNCREATE, then you can can create a object like
pRuntimeClassObj->CreateObject(). how to do in OCC.
thanks.
Sat, 08/31/2002 - 21:43
Hi,
I couldn't find any RTTI available in OCC for creating object, the following is the DEFINE_STANDARD_RTTI macro:
#define DEFINE_STANDARD_RTTI(C1) \
Standard_EXPORT friend Handle_Standard_Type& C1##_Type_(); \
Standard_EXPORT const Handle(Standard_Type)& DynamicType() const ; \
Standard_EXPORT Standard_Boolean IsKind(const Handle(Standard_Type)&) const ;
No any structure available for danamic creation.
But you can do it yourself. I write a very simple one: you can easily write your own.
#define DECLARE_DYNAMIC(classname)\
Handle_Standard_Transient yourCreate##classname();
#define IMPLEMENT_DYNAMIC(classname)\
Handle_Standard_Transient yourCreate##classname()\
{ return new classname; }
#define RUNTIME_CREATE(classname) yourCreate##classname()
of course, there must be a default constructor with classname. If you want to create a class by its string name as in Java, you can maintain a hash table to deal with it.
What I am most interested is: which application context in OCC is need this mechanism?
Can you tell me your design idea?
fhchina
Mon, 09/02/2002 - 04:32
Hi,
Yeah, your idea is good, but the the name of your macro is same as MFC's:-)
My idea of doing so is that I can create my object according to some other information, such as an id. I register all of the id with an runtime object such as Standard_Integer with an Standard_Type, then in future in my code, I will call like this:
getRuntimeObject()->CreateObject();
regards
Lugi.C
Mon, 09/02/2002 - 12:42
Hi,
Sorry, I forget we are both using MFC. :-)
regards,
fhchina