我是新手，hello程序有问题啊！不知道错那啊！
D:\Qt\a>mingw32-make
mingw32-make -f Makefile.Debug
mingw32-make[1]: Entering directory `D:/Qt/a'
g++ -c -g -frtti -fexceptions -mthreads -Wall -DUNICODE -DQT_LARGEFILE_SUPPORT -
DQT_DLL -DQT_GUI_LIB -DQT_CORE_LIB -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN -I"..\20
09.05\qt\include\QtCore" -I"..\2009.05\qt\include\QtGui" -I"..\2009.05\qt\includ
e" -I"." -I"..\2009.05\qt\include\ActiveQt" -I"debug" -I"..\2009.05\qt\mkspecs\w
in32-g++" -o debug\11.o 11.cpp
11.cpp: In function 'int qMain(int, char**)':
11.cpp:12: error: 'class QApplication' has no member named 'setMainWidget'
mingw32-make[1]: *** [debug/11.o] Error 1
mingw32-make[1]: Leaving directory `D:/Qt/a'
mingw32-make: *** [debug] Error 2
