static Singleton& GetInstance() { static std::once_flag s_flag; std::call_once(s_flag, [&]() { instance_.reset(new Singleton); }); return *instance_; } ~Singleton() = default; void PrintAddress() const { std::cout << this << std::endl; } Singleton(const Singleton&) = delete...
然后,分别将debug版、release版qBreakpad.lib拷贝至,qbreakpadlib\lib\debug和qbreakpadlib\lib\release目录下。 再将调用库所需的头文件QBreakpadHandler.h、QBreakpadHttpUploader.h、call_once.h、singleton.h共4个文件拷贝至qbreakpadlib\include下。call_conce.h 和 singleton.h 在singletone文件夹目录下,一起连...
1 // 1.QT_WIN_CALLBACK QtWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) bool QETWidget::translateMouseEvent(const MSG &msg) 2 // 2.bool QApplicationPrivate::sendMouseEvent(...) 3 // 3.inline bool QCoreApplication::sendSpontaneousEvent(QObject *receiver, QEvent *event)...
This virtual function is called once before the first call to paintGL() or resizeGL(). Reimplement it in a subclass.This function should set up any required OpenGL resources and state. There is no need to call makeCurrent() because this has already been done when this function is called....
E:/opencv/opencv-4.5.5/3rdparty/protobuf/src/google/protobuf/stubs/mutex.h:124:29: error: temporary of non-literal type 'google::protobuf::internal::CallOnceInitializedMutex<std::mutex>' in a constant expression constexpr WrappedMutex() {} ...
error: temporary of non-literal type 'google::protobuf::internal::CallOnceIn… 上网搜索了一下,发现原因在于Qt 5.14.2自带的MinGW编译器,不支持最新版本opencv中的protobuf(版本3.19)。而OpenCV 4.5.4版本中的protobuf版本是3.5.1,没有C++语法的新特性,因此不会出现问题。
virtual int qt_metacall(QMetaObject::Call, int, void **); \ QT_TR_FUNCTIONS \ 5.3 MOC 文件 接下来就是完成初始化的过程了,在编译前,会先执行 moc 程序(meta object compiler),生成 moc_MyClass.cpp,这个过程可以看作是找到有标记的文件,解析类的描述信息,生成的文件如下,其中删掉了一些不关键的自动...
QT GUI 编程 IQT介绍 Qt 是一个跨平台应用程序和 UI 开发框架 只需一次性开发应用程序,无须重新编写源代码,便可跨不同桌面和嵌入式操作系统部署这些应用程 序 Qt完全的面向对象易于扩展,并允许组件编程 Qt支持的平台 Embe
... // must be called with a locked mutex QLibraryStore *QLibraryStore::instance() { if (Q_UNLIKELY(!qt_library_data_once && !qt_library_data)) { // only create once per process lifetime qt_library_data = new QLibraryStore; qt_library_data_once = true; } return qt_library...
{ #ifdef Q_OS_WINCE // WinCE doesn't support hooks at all, so we have to call this by hand :( (void) qt_GetMessageHook(0, PM_REMOVE, (LPARAM) &msg);#endif if (d->internalHwnd == msg.hwnd && msg.message == WM_QT_SENDPOSTEDEVENTS) { if (seenWM_QT_SENDPOSTEDEVENTS) { /...