|
CoCreateInstance
Creates a single uninitialized object of the kind associated with the
specified CLSID and returns any requested interface pointer. Call CoCreateInstance when you want to create a single object based on a CLSID. If you want to
create multiple objects from a single class object, refer to the CoGetClassObject function.
STDAPI CoCreateInstance(
REFCLSID rclsid,
| //Class identifier
| LPUNKNOWN pUnkOuter,
| //Object is or isn't part of an aggregate
| DWORD dwClsContext,
| //Context for running executable code
| REFIID riid,
| //Interface identifier
| LPVOID * ppv
| //Pointer to storage of interface pointer
| );
|
|
Parameters
rclsid
Specifies the CLSID that will associate the correct data and code.
pUnkOuter
If NULL, indicates that the object is not being created as part of an aggregate. If
non-NULL, points to the controlling unknown of the aggregate that will use the newly
created object.
dwClsContext
Specifies the context in which the executable is to be run. The values are
taken from the enumeration CLSCTX.
riid
Specifies the interface to be used to communicate with the object.
ppv
Points to where to return the pointer to the requested interface.
Return Values
S_OK
Indicates that an instance of the specified object class was successfully
created.
REGDB_E_CLASSNOTREG
Indicates that a specified class is not registered in the registration
database.
E_OUTOFMEMORY
Out of memory.
E_INVALIDARG
Indicates one or more arguments are invalid.
E_UNEXPECTED
Indicates an unexpected error occurred.
CLASS_E_NOAGGREGATION
Indicates this class cannot be created as part of an aggregate.
Comments
The CoCreateInstance helper function connects to the class object associated with the specified
CLSID, creates an uninitialized instance, and releases the class object. It
encapsulates the following functionality:
CoGetClassObject(rclsid, dwClsContext, NULL, IID_IClassFactory,
&pCF);
hresult = pCF->CreateInstance(pUnkOuter, riid, ppvObj)
pCF->Release();
It is convenient to use this function when you need to create only a single
instance through a class object, and do not need to keep the class object around
to create other instances. If you do, see the CoGetClassObject function.
See Also
CoGetClassObject, IClassFactory::CreateInstance
Related LinksSoftware for Delphi and C++ Builder developers
Software for Visual Studio .NET developers
Software for Visual Basic 6 developers
Delphi Tips&Tricks
MegaDetailed.NET More Online Helps Win32 Programmer's Reference (win32.hlp)
Win32 Multimedia Programmer's Reference (mmedia.hlp)
Microsoft Windows Pen API Programmer's Reference (penapi.hlp)
Microsoft Windows Sockets 2 Reference (sock2.hlp)
Microsoft Windows Telephony API (TAPI) Programmer's Reference (sock2.hlp)
Unix Manual Pages
|
