我想编译Qt示例。我遇到了错误的QtWidgets:没有这个文件或目录 #include
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets - does not help
QT += widgets - does not help
INCLUDEPATH += /opt/Qt/5.3/Src/qtbase/include/ - does not help
Qt 5.3. Ubuntu 14.04 x64.