IStdMarshalInfo

The IStdMarshalInfo interface returns the CLSID identifying the handler to be used in the destination process during standard marshaling.

An object that uses OLE's default implementation of IMarshal does not provide its own proxy but, by implementing IStdMarshalInfo, can nevertheless specify a handler to be loaded in the client process. Such a handler would typically handle certain requests in-process and use OLE's default marshaling to delegate others back to the original object.

To create an instance of an object in some client process, COM must first determine whether the object uses default marshaling or its own implementation. If the object uses default marshaling, COM then queries the object to determine whether it uses a special handler or, simply, OLE's default proxy. To get the CLSID of the handler to be loaded, COM queries the object for the IStdMarshalInfo interface and then the IPersist interface. If neither interface is supported, a standard handler is used.

When to Implement

If you are writing a server application that supports class emulation (that is, if your server can manipulate objects of another type in response to the Activate As option in the Convert dialog box), you must implement the IStdMarshalInfo interface in order to return the CLSID of the handler to be used for the object.

Note that your handler must aggregate the default handler.

When to Use

You typically don't call this interface yourself. COM queries for this interface when performing standard marshaling.

Methods in VTable Order

IUnknown Methods Description
QueryInterface Returns pointers to supported interfaces.
AddRef Increments reference count.
Release Decrements reference count.

IStdMarshalInfo Method Description
GetClassForHandler Obtains the class identifier of the object handler in the destination process.

QuickInfo

  Windows NT: Use version 3.1 or later.
  Windows: Use Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in objidl.h.

See Also

IMarshal