DispSink Attributes Sample: Handles Events Fired from a Singleton COM Server Through a Dispatch Interface
The DispSink attributes sample demonstrates a singleton server object (an object that can have only one instance) that has its own dual interface and a dispatch interface used for firing off events.
The DispSink sample is the nonattributed version of this sample.
This sample may not exactly demonstrate some features of the Visual C++ wizards, libraries, and compiler, but it still shows how to complete the intended task.
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On the Help menu, click Samples.
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To build and run this sample
Open the solution file DispSink.sln.
From the Build menu, click Build Solution.
Open two or more instances of the ActiveX Control Test Container and insert the client control, DispCtl, into each instance. See Testing Properties and Events with Test Container for information on how to access the test container.
Invoke the Connectmethod on all of the controls.
Invoke the Send method on one of the controls. Change the Parameter Type field of the Invoke Methods dialog box to VT_BSTR and then type any string into the Parameter Value box. Click the Invoke button. The string will be displayed in the center of all connected controls.
Invoke the Disconnect method on all controls prior to deleting them.
The server is a singleton object that has its own dual interface as well as a dispatch interface used for firing off events. The dispatch interface is placed in the .idl file using the dispinterface attribute. The server object receives data through its dual interface Send method and transmits it to all connected components through the Transfer event on its dispatch interface. The Dispserver uses the event_source attribute, and the Dispclient uses the event_receiver attribute.
The client is an ActiveX control that contains a server object. The control responds to the Transfer event fired by the server object. It has a dual interface that has Connect, Send, and Disconnect methods. If the Transfer event is fired with a variant containing a BSTR, the string is displayed in the center of the control.
This sample uses the following attributes:
DISPSINK/DispClient coclass, dual, event_receiver, helpstring, id, module, object, pointer_default, registration_script, threading, uuid, version, vi_progid
DISPSINK/DispServer coclass, default, dispinterface, dual, event_source, helpstring, id, module, object, pointer_default, threading, uuid, vi_progid