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VB ActiveX Does Not Support Externally Defined Events

* If you define an interface in a Type Library and implement it in Visual Basic, no problem.

* For example, if you define an interface ITestInterface in a Type Library and then have your VB ActiveX project reference this type lib, the following statement goes fine :

Implements ITestInterface

* However, if you define a source (i.e. event) interface in a Type Library and try to have a Visual Basic ActiveX raise its events via RaiseEvent statements, not possible.

* For example, if you define a dispinterface _ITestEvents with event Event01() in a Type Library and then have your VB ActiveX Project raise it as follows :

RaiseEvent Event01()

The VB Compiler will complain of an unidentified event.

If you try to raise it as follows :

RaiseEvent <typelibraryname>.Event01()

The compiler will not complain but it still won't work. The problem is that _ITestEvents will not be recognized as being a source interface of the ActiveX.

* If we try to define the events of _ITestEvents in the declaration of the ActiveX itself, e.g. :

Public Event Event01()

The ActiveX will then declare a source interface for itself and Event01() will be absorbed into this default source event set, i.e. you will find the following declarations when you observe the TLB generated for the ActiveX :

coclass clsVBActiveX
{
...
...
...
[default, source] dispinterface __clsVBActiveX;
};

...
...
...
dispinterface __clsVBActiveX
{
void Event01();
};

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