CoGetClassObject

Provides a pointer to an interface on a class object associated with a specified CLSID. CoGetClassObject locates, and if necessary, dynamically loads the executable code required to do this.

Call CoGetClassObject directly when you want to create multiple objects through a class object for which there is a CLSID in the system registry. You can also retrieve a class object from a specific remote machine. Most class objects implement the IClassFactory interface. You would then call IClassFactory::CreateInstance to create an uninitialized object. It is not always necessary to go through this process. To create a single object, call instead the either the CoCreateInstanceEx function, which allows you to create an instance on a remote machine. This replaces the CoCreateInstance function, which can still be used to create an instance on a local machine. Both functions encapsulate connecting to the class object, creating the instance, and releasing the class object. Two other functions, CoGetInstanceFromFile and CoGetInstanceFromIStorage, provide both instance creation on a remote system, and object activation. OLE also provides many other ways to create an object in the form of numerous helper functions and interface methods whose function is to create objects of a single type and provide a pointer to an interface on that object.

b.

IClassFactory::CreateInstance

Creates an uninitialized object.

2 通過CoCreateInstance

CoCreateInstance

Creates a single uninitialized object of the class associated with a specified CLSID. Call CoCreateInstance when you want to create only one object on the local system. To create a single object on a remote system, call CoCreateInstanceEx. To create multiple objects based on a single CLSID, refer to the CoGetClassObject function.

第二種方法就是把第一種方法的兩個函數合并了。

也就是說把貓叫了個咪。