出现如下错误信息:
think@ubuntu:~/桌面/qt-book/chap01/hello$ make
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o hello.o hello.cpp
hello.cpp:1:24: error: QApplication: 没有那个文件或目录
hello.cpp:2:18: error: QLabel: 没有那个文件或目录
hello.cpp: In function ‘int main(int, char**)’:
hello.cpp:6: error: ‘QApplication’ was not declared in this scope
hello.cpp:6: error: expected ‘;’ before ‘app’
hello.cpp:7: error: ‘QLabel’ was not declared in this scope
hello.cpp:7: error: ‘label’ was not declared in this scope
hello.cpp:7: error: expected type-specifier before ‘QLabel’
hello.cpp:7: error: expected ‘;’ before ‘QLabel’
hello.cpp:9: error: ‘app’ was not declared in this scope
hello.cpp: At global scope:
hello.cpp:4: warning: unused parameter ‘argc’
hello.cpp:4: warning: unused parameter ‘argv’
make: *** [hello.o] 错误 1