# .pro文件
QT += widgets
requires(qtConfig(filedialog))
HEADERS = mainwindow.h
SOURCES = main.cpp \
mainwindow.cpp
RESOURCES = sdi.qrc
# install
target.path = $$[QT_INSTALL_EXAMPLES]/widgets/mainwindows/sdi
INSTALLS += target
DISTFILES += \
document1.txt
## requires(qtConfig(filedialog))
在Qt中,requires(qtConfig(filedialog)) 是一种条件编译的语法。它用于在编译和构建过程中检查是否启用了文件对话框功