[Qgis-developer] multimap object dereferencing in a plugin

[maaza mekuria]

I have been trying hard to find how to get access to the object I stored in a QMultiMap container. I am able to retrieve the numbered keys but when I try accessing the object QGIS crashes. 

I have done similar work in plain C++ and it has worked with out any problem, I used regualr multimap before. Here I tried both QT multimap and regualr multimap and while trying to access the second item in the iterator QGIS seems to give up. Any help will be appreciated. I have pasted a piece of the code below,    


   typedef QMultiMap<long,QgsPoint> mmaplngQPt;
// QgsPoint map iterator objects
   typedef mmaplngQPt::iterator maplngQPtit1, maplngQPtit2;
   mmaplngQPt::iterator Pt1Qmapit, Pt2Qmapit,itQlow, itQup;
   typedef pair < long, QgsPoint >  QPt_pair;
   mmaplngPt mapQPt,mapQPt0,mapQPt1;
   mmaplngPt::iterator mapQPtit;
   long iKey;
   int lbx,ubx;
  QgsPoint vx;

   itQlow=mapQPt.lowerBound (lbX);
   itQup=mapQPt.upperBound (ubX);

                  for ( mapQPtit=itQlow ; mapQPtit != itQup; mapQPtit++ ) 
                  {

                     txtStream <<"key = "<<itQlow.key()<<endl;
                                                        iKey = (QPt1mapit).key();
                     vx = (QPt1mapit).value();

                                                 }



The program crashes write after it prints the key value. By the way any way of finding a meaningful error message in QGIS?

Thank you,

Maaza
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