ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH C++ AND CONTROL WIDGETS
IEventListenerHelperPtr g_ipTOCControlEventHelper;
TransformEvents* g_transEvents;
IEventListenerHelperPtr g_ipTransEventHelper;
…
int main (int argc, char* argv[])
{
…
g_ipTOCControlEventHelper->AdviseEvents(g_ipTOCControl, NULL);
g_transEvents = new TransformEvents();
g_ipTransEventHelper.CreateInstance(CLSID_TransformEventsListener);
g_ipTransEventHelper->Startup(
static_cast (g_transEvents));
…
}
9. You need to trap for the TransformEvents from the PageLayoutControlEvents
OnPageLayoutReplaced event.
a. To do this PageLayoutControlEvents will need to know about
g_ipTransEventHelper, so declare it with extern in
PageLayoutControlEvents.h.
extern IEnvelopePtr g_ipCurrentExtent;
extern IEventListenerHelperPtr g_ipTransEventHelper;
b. Now advise the events in OnPageLayoutReplaced:
void PageLayoutControlEvents::OnPageLayoutReplaced(VARIANT newPageLayout)
{
// Get the extent of the PageLayout's focus map
IActiveViewPtr ipActiveView;
g_ipPageLayoutControl->get_ActiveView(&ipActiveView);
IMapPtr ipFocusMap;
ipActiveView->get_FocusMap(&ipFocusMap);
IActiveViewPtr ipMapActiveView = ipFocusMap;
ipMapActiveView->get_Extent(&g_ipCurrentExtent);
// Trap focus map's ITransformEvents
IScreenDisplayPtr ipScreenDisp;
ipMapActiveView->get_ScreenDisplay(&ipScreenDisp);
IDisplayTransformationPtr ipDisplayTrans;
ipScreenDisp->get_DisplayTransformation(&ipDisplayTrans);
CComBSTR bsGUID;
::StringFromIID(IID_ITransformEvents, &bsGUID);
IUIDPtr ipUID(CLSID_UID);
ipUID->put_Value(CComVariant(bsGUID));
g_ipTransEventHelper->AdviseEvents(ipDisplayTrans, ipUID);
// Load the same pre-authored map document into the MapControl
…
}
Chapter 6 • Developer scenarios • 387