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ActiveX controls in VFP
>While I was searching on the net, I did read an article which tells that , VFP does not support active-x object which uses callback. Actually I don't have any idea what CALLBACK means.
>So is it true ? If so what could be the solution if we want to use this type of active-x ?
If I understand correctly, callback is when a class is implemented by VFP inbehalf of the active-x.
There might be a particular case where the programmer of the active-x will allow the end-developer to influence certain behavior. In this case the definition class is implemented in VFP and VFP does support this (at least in VFP9). This is accomplished by defining a VFP class with the IMPLEMENTING keyword and a reference to the active-x class (could be GUID). Then the VFP developer would register the class with the active-x via the interface provided by the active-x developer. I have done this in several programs; note that the performance is impacted when the VFP debugger is open when the callbacks are being called (slowed down due to debugger).
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