I was using MSVC++ to compile my qt codes and I decided to use QtCreator from now on
however the problem is I can't compile my existing code in this enviroment. I also use qwt dlls in my code and I couldn't get it to work although I added the lib path just like you said to the PATH variable.
The error I get is:

Qt Code: 
  1. error: undefined reference to`QwtPlotMarker::setXValue(double)'
  2. error: undefined reference to `QwtPlotGrid::enableXmin(bool)'
  3. ... many other qwt components but the same error
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these errors are raising from a cpp file which includes (everything I use, and it was enough for MSVC++ enviroment ) :

Qt Code: 
  1. #include <qwt_plot.h>
  2. #include <qwt_plot_curve.h>
  3. #include <qwt_plot_zoomer.h>
  4. #include <qwt_legend.h>
  5. #include <qwt_plot_marker.h>
  6. #include <qwt_symbol.h>
  7. #include <qwt_legend_item.h>
  8. #include <qwt_plot_grid.h>
  9. #include <qwt_painter.h>
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interestingly intelli-sense recognize all of these variables..
anyways here is the .pro file I'm using:

Qt Code: 
  1. TARGET = myProgramsName
  2. CONFIG += qt thread release console
  3. CONFIG -= flat
  4. CONFIG -= console
  5. QT += xml
  6. MOC_DIR = moc
  7. UI_DIR = UI
  8.  
  9. FORMS +=  allmyUIFiles
  10.  
  11. RESOURCES += source/GUI/ui.qrc
  12.  
  13. win32 {
  14.  RC_FILE = source/GUI/mcmm-gui.rc
  15.  
  16.   INCLUDEPATH += d:/qt-all-opensource-src-4.4.0/qwt-5.1.1/include/
  17.  
  18.  LIBS +=  -L"source\mcmm" -lqwt5 \
  19.  
  20. }
  21.  
  22. HEADERS +=  paths of all headers files..  
  23.  
  24. SOURCES += paths of all my source codes..
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I guess the key thing is here the INCLUDEPATH and LIBS
I copied qwt5.lib to my source folder thinking that giving the full path instead would be causing the problem, however didn't solve anything..

I've also tried (Instead of the "-L" and "-l" tags):

Qt Code: 
  1. LIBS +=  source\mcmm\qwt5.lib
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I'm a little bit lost here, please help!