IClassFactory

The IClassFactory interface contains two methods intended to deal with an entire class of objects, and so is implemented on the class object for a specific class of objects (identified by a CLSID). The first method, CreateInstance, creates an uninitialized object of a specified CLSID, and the second, LockServer, locks the object's server in memory, allowing new objects to be created more quickly.

When to Implement

You must implement this interface for every class that you register in the system registry and to which you assign a CLSID, so objects of that class can be created.

When to Use

After calling the CoGetClassObject function to get an IClassFactory interface pointer to the class object, call the CreateInstance method of this interface to create a new uninitialized object.

It is not, however, always necessary to go through this process to create an object. To create a single uninitialized object, you can, instead, just call CoCreateInstance. OLE also provides numerous helper functions (with names of the form OleCreateXxx) to create compound document objects.

Call the LockServer method to keep the object server in memory and enhance performance only if you intend to create more than one object of the specified class.

Methods in Vtable Order

QuickInfo

  Windows NT: Use version 3.1 or later.
  Windows: Use Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in unknwn.h.

See Also

CoGetClassObject, CoCreateInstance, OleCreate