IMarshal::GetMarshalSizeMax - OLE Programmer's Reference (ole.hlp)

IMarshal::GetMarshalSizeMax

Returns an upper bound on the amount of data that would be written to the marshaling stream in a call to IMarshal::MarshalInterface.

HRESULT IMarshal::GetMarshalSizeMax(

REFIID riid,	//Identifies interface to be marshaled
void *pv,	//Points to interface pointer to be marshaled
DWORD dwDestContext,	//Identifies destination process
void * pvDestContext,	//Reserved for future use
DWORD mshlflags,	//Specifies reason for marshaling
ULONG * pSize	//Receives upper bound
);

Parameters
riid

[in]Specifies the IID of the interface pointer to be marshaled.

[in]Points to the interface pointer to be marshaled; can be NULL.

dwDestContext

[in] Specifies the destination context, that is, the process in which the unmarshaling will be done. Different marshaling can be done depending on whether the unmarshaling will happen on the local workstation or on a workstation on the network; it's possible for an object to do custom marshaling in one case but not another. The legal values for dwDestContext are taken from the enumeration MSHCTX. For information on the MSHCTX enumeration, see the "Data Structures" section.

pvDestContext

[in] Reserved for use with future MSHCTX values.

mshlflags

[in] Specifies why marshaling is taking place. The legal values for mshlflags are taken from the enumeration MSHLFLAGS. For information on the MSHLFLAGS enumeration, see the "Data Structures" section.

pSize

[out]Receives the upper bound on the amount of data that would be written to the marshaling stream.

Return Values
S_OK

Maximum size was returned successfully.

E_FAIL

Indicates that the implementation failed.

E_NOINTERFACE

The specified interface was not supported.

Comments
This method is called from the originating side (that is, the side doing the marshaling). This method is used to preallocate the stream buffer that will be passed to IMarshal::MarshalInterface.

Notes to Implementors
The value your implementation returns must be an upper bound; a subsequent call to your implementation of IMarshal::MarshalInterface must use no more than the number of bytes returned by this method. The upper bound you return can be used by the caller to preallocate a stream buffer for using during marshaling.