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This function destroys a previously marshaled data packet.
Syntax
STDAPI CoReleaseMarshalData( IStream* pStm ); |
Parameters
- pStm
-
[in] Pointer to the stream that contains the data packet to be destroyed.
Return Value
This function supports the standard return values E_FAIL, E_INVALIDARG,
E_OUTOFMEMORY, and E_UNEXPECTED, as well as the following:
- S_OK
-
The data packet was successfully destroyed.
- STG_E_INVALIDPOINTER
-
An IStreamerror dealing with the pStmparameter.
- CO_E_NOTINITIALIZED
-
The CoInitializefunction was not called on the current thread before this function was called.
Remarks
The CoReleaseMarshalDatafunction performs the following tasks:
- The function reads a CLSID from the stream.
- If COM's default marshaling implementation is being used, the
function gets an
IMarshalpointer to an instance of the standard unmarshaler.
If custom marshaling is being used, the function creates a proxy by calling the CoCreateInstancefunction, passing the CLSID it read from the stream, and requesting an IMarshalinterface pointer to the newly created proxy. - Using whichever
IMarshalinterface pointer it has acquired, the function
calls
IMarshal::ReleaseMarshalData.
Typically your application will not call this function. It might need to call this function only if using custom marshaling to write and use a special implementation of IMarshal. The following are examples of situations for which CoReleaseMarshalDatashould be called:
- A failed attempt has been made to unmarshal the data packet.
- A marshaled data packet has been removed from a global table.
As an analogy, the data packet can be thought of as a reference to the original object, just as if it were another interface pointer being held on the object. Like a real interface pointer, that data packet must be released at some point. The use of IMarshal::ReleaseMarshalDatato release data packets is analogous to the use of IUnknown::Releaseto release interface pointers.
Note that your application does not need to call CoReleaseMarshalDataafter a successful call of the CoUnmarshalInterfacefunction. That function releases the marshal data as part of its processing.
To determine whether the platform supports this function, see Determining Supported COM APIs.
Requirements
Header | objbase.h |
Library | ole32.lib |
Windows Embedded CE | Windows CE 3.0 and later |
Windows Mobile | Windows Mobile Version 5.0 and later |