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.
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.
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
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IUnknown Methods |
Description |
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Returns pointers to supported interfaces. | |
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Increments reference count. | |
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Decrements reference count. |
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IClassFactory Methods |
Description |
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Creates an uninitialized object. | |
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Locks object application open in memory. |
See Also