KB153881 - HOWTO: How To Assign the ActiveX Control LPDispatch Property in VB 4

MORE INFORMATION

Follow these steps to add a property to a custom ActiveX control that is to hold another control's IDispatch pointer:

Using ClassWizard, add a property of type LPDispatch to the control. Fill in a name for the property, and select the "Member Variable" button for this property.
Next, you must initialize this member variable to NULL in the control's constructor. If you do not, Visual Basic will cause a General Protection Fault when you try to assign a value to it. This occurs because MFC tries to call Release() on the uninitialized pointer. If the pointer is set to NULL, Release() will not be called by MFC.
Build the control, and place it on a form in Visual Basic.

The following lines of Visual Basic code demonstrate how to set the property to another control's IDispatch pointer:

   'Set the control's DispatchProp property to the DBCombo OLE control on
   'this form.
   Set MyOcx1.DispatchProp = DBCombo1

     . . .
     . . .

   'Don't forget to set this property to Nothing when finished
   Set MyOcx1.DispatchProp = Nothing

REFERENCES

HOWTO: How To Assign the ActiveX Control LPDispatch Property in VB 4

SUMMARY

MORE INFORMATION