• Posting events with QApplication::postEvent(), or using queued signal/slot connections, are both safe mechanisms for communicating across threads but require the receiving thread. ) このような場合は以下の通り qRegisterMetaType() の引数を設定することで回避できることがある。You can safely remove the const, even if the real signature of SendData and ReceiveData is const u_char*. Also you may need to use qRegisterMetaType function. So the image buffer is maintained internally and thus implicitely shared. Steps to reproduce. When: when you need to pass arguments to a queued connection or to enable creation of objects at run-time. You can safely remove the const, even if the real signature of SendData and ReceiveData is const u_char*. Adding a Q_DECLARE_METATYPE() makes the type known to all template based functions, including QVariant. One of these objects is a Connection. You have to register your custom type for queued signals because by registering it, Qt can make a copy of it in its event loop (which certainly uses QVariant) and pass it as argument later (when the original passed value is long since out. ) I read on some forum, that this may be caused by calling qt-functions from another Thread, and that using signals & slots instead of plain function calling may fix the issue, but i have tried signals aswell, and i. Where are you getting this from? qRegisterMetaType is not a member function of QSettings or any other class. Now you have a valid QObject. TheIt is safe to call qRegisterMetaType() more than once. Not sure yet. 步骤： (以自定义MyDataType类型为例）. . Note that, as far as the meta-type system is concerned, MyClass, MyClass *, QVector<MyClass>, shared_ptr<MyClass> and so on are all different types, and as such, each one may need its own registration. Qt documentation specifically states that qRegisterMetaType<T>() must be called for a type to work in the Qt property system. Returns true if the write succeeded; otherwise returns false. This topic has been deleted. 1 Reply Last reply 0. You could also Q_DECLARE_METATYPE to register your custom type and then use qMetaTypeId () to get the metaType id. " Currently I have no UI implemented (yet!). e. PySide2. For the moment, moc will extract and record all tags, but it will not handle any of them specially. October 21, 2020 by Fabian Kosmale | Comments As you might know, Qt has a metatype system which provides run-time dynamic information about types. If you are using queued connections, you need to register std::string as meta type. program exits if. 1 Answer. You don't have to register your data type via qRegisterMetaType, and when you send your data as a reference it is not copied. This class can tell the outside world that its state has changed by emitting a signal, valueChanged(), and it has a slot which other objects can send signals to. So if you put the register in constructor, you have to instance your class once and then make the connection. 1 Answer. See also disconnect(), sender(), qRegisterMetaType(), Q_DECLARE_METATYPE(), and Differences between String-Based and Functor-Based Connections. qRegisterMetaType <Card::Orientation> ( "Card::Orientation" ); QSignalSpy. like this: class ListPage : public QWizardPage { Q_OBJECT Q_PROPERTY (QItemSelectionModel* selectionModel READ selectionModel) public:. ) QObject::connect: Cannot queue arguments of. This implies that you can create bindings that use this property as a dependency or install QPropertyObserver objects on this property. To not see the message. uint8_t is the typedef for unsigned char . 如果要使自定义类型或其他非QMetaType内置类型在QVaiant中使用，必须使用该宏。. Type "MyType" has id: 1024 ; register status: true QObject::connect: Cannot queue arguments of type 'MyType' (Make sure 'MyType' is registered using qRegisterMetaType(). The difference between Qt::QueuedConnection and Qt::AutoConnection is due to a difference in the. Reproducible Example Of The. @SGaist Yes, I am using it with QVariant, mostly with QSettings to save and retrieve data easily by overriding QDataStream operators. Be very careful as cv::Mat is not implicitly shared, it is just shared (i. However, if I add the const qualifier in front of Person* p in the argument list of test () I get errors from QML at run-time! (i. 1. Data Type Conversion Between QML and C++. In C++ if you wan't to use some type in queued connection type you should call qRegisterMetaType<MyType> ("MyType"). It can be used to check if the connection is valid and to disconnect it using disconnect(). ) QObject: Cannot create children for a parent that is in a different thread. qmlRegisterUncreatableType# qmlRegisterUncreatableType (pytype: type, uri: str, versionMajor. Hello, Can someone tell me about how to register a metatype in pyqt5. The Custom Type, Custom Type Sending and Queued Custom Type examples show how to implement a custom type with the features outlined in this document. There is no use case for implementing qRegisterMetaType, because PyObject. For pointer types, it also requires that the pointed to type is fully defined. The Qt doc on qRegisterMetaType explicitly says : T must be declared with Q_DECLARE_METATYPE (). Using qRegisterMetaType() is actually registering a certain type to QMetaType. The Rep lica C ompiler (repc) generates QObject header files based on an API definition file. ) QObject::connect: Cannot queue arguments of type 'QVector' (Make sure 'QVector' is registered using qRegisterMetaType(). As said in int qRegisterMetaType () documentation: To use the type T in QVariant, using Q_DECLARE_METATYPE () is sufficient. If the Microsoft compiler was not requiring this, then it was doing it wrong. Attention: Answers. The habit of passing shared_ptr by ref should not be followed in lambdas. Specifically, the function have to be called before using the struct in a queued signal/slot connection or. goocreations 12 Mar 2013, 07:22. QNativeSocketEngine::write () was not called in QAbstractSocket::ConnectedState. The SplitBehavior type is a typedef for QFlags <SplitBehaviorFlags>. It enables storing your types in QVariant, queued connections in. It can be done with some global container, but because in C++ order of initializing variables is not defined - it may be not trivial. It was also no big issue to call qRegisterMetaType () automatically. d. The entries are addressed via startAddress () and the valueCount () number of contiguous entries. Instead, the enum should be registered as soon as the shared library is loaded. QVariant’s operator== now uses QMetaType::equals for the comparison. I understand that it has to do with Qt library but in which cpp file i have to put the argument ? The argument is this right ? qRegisterMetaType<QVector<int> >. a copy of a cv::Mat object will point to the same data as the copied from item). Thus the following will fail. qRegisterMetaType () is called to register the TYPE and generate a TYPE ID. clicked. 我们知道类中的成员函数并不一定会被调用(即，该宏并不确保类型被注册到MetaType)。 通过qRegisterMetaType可以确保类型被注册 ; 两个qRegisterMetaType 的联系QObject::connect: Cannot queue arguments of type 'QHostAddress' (Make sure 'QHostAddress' is registered using qRegisterMetaType(). Represents a handle to a signal-slot (or signal-functor) connection. Any class or struct that has a public default constructor, a public copy constructor , and a. 048771190]: Out drawPath [ INFO] [1432901455. To call qRegisterMetaType (), you still need to use Q_DECLARE_METATYPE (). cpp file. Sep 21, 2015 at 14:17. You can use the tags to annotate your methods. When I try to build our existing. The QML engine provides built-in support for a large number. In variant 1 the call is invoked immediately like in direct connection. tabs. 2] enum QLocalSocket:: SocketOption flags QLocalSocket:: SocketOptions This enum describes the possible options that can be used to connect to a server. And this should be used for each exe/dll instance. setContextProperty qmlRegisterType qRegisterMetaType等区别. In QML, the meta-type system is the only way that QML engine can access C++ structures from a QML environment. Add a comment | 5 I believe the following is state is not defined in your MyThread class. g. You have to register your custom type for queued signals because by registering it, Qt can make a copy of it in its event loop (which certainly uses QVariant) and pass it as argument later (when the original passed value is long since out of. But the problem comes up when I try to send it to C++ slot, that have my enum as parameter. You could wrap the used functions and classes into custom widgets or plain py-files and in your main frame class only import those custom widgets. Yet, the first line is invisible and this line becomes visible only if we click on it! Very weird! QObject::connect: Cannot queue arguments of type 'QTextCursor'. ) It's a bit tricky thing. (Make sure 'QVector' is registered using qRegisterMetaType(). Call qRegisterMetaType() to make type available to non-template based functions, such as the queued signal and slot connections. qmlRegisterType<Person> ("People", 1,0, "Person"); This would register the C++ class "Person" as a QML element also called "Person", into the module "People" under the version 1. emit (statuses) Share. Got a similar example working without explicitly calling qRegisterMetaType() just by removing the semicolon from the line Q_DECLARE_METATYPE(StateMachine::state) QObject::connect: Cannot queue arguments of type 'QModbusDevice::State' (Make sure 'QModbusDevice::State' is registered using qRegisterMetaType (). Although I have not made clear the specific meaning, at least it can work well. ) QObject::connect: Cannot queue arguments of type 'QModelIndex' (Make sure 'QModelIndex' is registed using qRegisterMetaType(). You can use the tags to annotate your methods. Also, to use type T with the QObject::property () API,. Saved searches Use saved searches to filter your results more quicklyI get a solution to the problem of "Qmqtt QObject::connect: Cannot queue arguments of type 'ClientState' (Make sure 'ClientState' is registered using qRegisterMetaType(). multithreaded software and I am getting the warning says: (Make sure. The Windows registry and INI files use case-insensitive keys, whereas the CFPreferences API on macOS and iOS uses case. Sets the port on the local side of a connection to port. g. rows += self. You can try it:This function registers the Python type in the QML system with the name qmlName, in the library imported from uri having the version number composed from versionMajor and versionMinor. Sets the factory to use for creating QNetworkAccessManager (s). The signature of your signal does not match the signature of what you wrote in the SIGNAL macro -- those are non-const references:. iv. QtのAPIのドキュメントに、thread-safeと書いてない限りは、QMutex等を使って自分で排他をする必要がある。. #include <QObject> #include <QVariant> class Record : public QPair<qreal, qreal> {. e. Note that this only works for QObject subclasses which use the Q_OBJECT macro. 0. An "ugly solution" would be to hack the fairly simple QSignalSpy code in order to handle the reference passed arguments. However, I cannot figure out how to verify that the included parameter is FACE_UP or FACE_DOWN. The same plugin may be loaded multiple times during the application's lifetime. Following this logic, the following code may not work: connect (senderObject. However documentation of qRegisterMetaType() says: "Call this function to. I am trying to learn Qt and I am attempting to do so by making a little titres game. e. PySide6. QSignalSpy can connect to any signal of any object and records its emission. Any class or struct that has a public default. Thanks for the code snippet. Now it works fine when pressButtonInsert is triggered but returns this. MainWindow win; win. Qt documentation specifically states that qRegisterMetaType<T>() must be called for a type to work in the Qt property system. Returns true if the column is inserted; otherwise returns false. Did you try to use qRegisterMetaType function? The official manual says: The class is used as a helper to marshall types in QVariant and in queued signals and slots connections. childKeys();@J. The following code: self. The QML engine provides built-in support for a. ) Nothing special is printed to the execution log. If you are using a version of PySide that somehow exposes qRegisterMetaType, it's a bug. – thuga. (Make sure. 5] int qRegisterMetaType (QMetaType meta) Registers the meta type meta and returns its type Id. Consider the specific case of qRegisterMetaType. registerType () determines which register is used for the operations. adam-iris added a commit that referenced this issue Oct 10, 2017. I tested your code on Qt 5. This enum was introduced or modified in Qt 5. 4. Using Q_ENUM () allows you to retrieve at run-time the name of an enum value: The class in Qt responsible for custom types is QMetaType. 16. In addition to the limitations of the variadic invoke() overload, the arguments must have the same type as the ones expected by the method, else, the behavior is. You are looking for the Q_ENUM () macro. QObject. Returns the internal ID used by QMetaType. uint8_t is the typedef for unsigned char . This line has disappeared in Qt 5. When I want to run hector_geotiff to print map in a existed map , rosrun hector_geotiff geotiff_saver , Some thing happens. 1 Reply Last reply . 1 Answer. 0, so Q_ENUM is my variant. Fixed a Qt warning about "cannot queue arguments of type. Then the TYPE ID is saved in local static vairable metatype_id. The questions are:在Qt使用moveToThread() qt的线程 笔记： 使用中：子线程要向主线程发送 QMap<QString, QString> 类型的变量. ; Create a native socket descriptor, instantiate QAbstractSocket, and call setSocketDescriptor() to wrap the native socket. 150%) wider. (Parent is QTcpSocket (0x24a6ce8), parent's thread is ServiceSlots (0xea66488), current thread is QThread (0x2418a78) See also qRegisterMetaType(). What is(are) the good place(s) to put the qRegisterMetaType call? I obviously don't want any expllicit initialization call from application code. cpp. can include digits and underscore). QObject::connect: Cannot queue arguments of type 'uint32_t' (Make sure 'uint32_t' is registered using qRegisterMetaType(). M. Call qRegisterMetaType () to make type available to non-template based. ) It plans for a new trajectory just Okay, but when I try to execute the planned trajectory it gives me the following errors:your struct or simple class must have Q_GADGET as minimum; you should declare properties in order to access from qml; you must declare your struct/class by Q_DECLARE_METATYPE(); you must register it using qRegisterMetaType<>() somewhere before loading qml file by engine such as main. Share. ) QObject: Cannot create children for a parent that is in a different thread. h which looks like: #ifndef ENUMS_H #define ENUMS_H #include <QtDBus> #include "enumDBus. Also, to use type T with the QObject::property() API, qRegisterMetaType() must be called before it is used, typically in the constructor of the. By convention, these files are given a . h. The QItemSelection class is one of the Model/View Classes and is part of Qt's model/view framework. )" caused by working in threads. Any class or struct that has a public default constructor, a public copy constructor and a public destructor can be registered in QMetaType. Call qRegisterMetaType () to make type available to non-template based functions, such as the queued signal and slot connections. pro file: CONFIG += qmltypes. Following this logic, the following code may not work: connect (senderObject. I also have to implement for cv::Mat type data. I'm running the livox horizon lidar on one PC and running the loam on a different PC. connect(self. ) # 切换rviz配置文件 terminate called after throwing an instan. If the signal is being emitted, I get this error: @. Detailed Description. struct StandardData { int EmpId; QString Name; }; Q_DECLARE_METATYPE (StandardData) Additionally, you might need to call qRegisterMetaType. 5. Any class or struct that has a public default constructor, a public copy constructor and a public destructor can be registered in QMetaType. すべてのソケットで読み書きができるようになりました。しかし、これらすべてのインスタンスをオーケストレーションするためのサーバがまだ必要です。4. 0. According to the Qt docs for qRegisterMetaType "Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. (异步调用) Qt::BlockingQueuedConnection，则将以与Qt :: QueuedConnection相同的方式调用该方法，除了当前线程将阻塞直到事件被传递。. My original script use this : from PyQt5. – pmf Feb 7, 2019 at 16:35 QObject::connect: Cannot queue arguments of type 'QTextCursor' (Make sure 'QTextCursor' is registered using qRegisterMetaType(). – folibis. Oct 17, 2014 at 14:12. This is the same as indexOfMethod (), except that it will return -1 if the method exists but isn't a signal. qRegisterMetaType<FileNodePointer> ("FileNodePointer"); should be called once (in main, constructor etc. That's created by this macro. on top of main. When the Citizen object is moved to the new thread the QNetworkAccessmanager still has its thread affinity set to. constData ()), " qRegisterNormalizedMetaType ", " qRegisterNormalizedMetaType was called with a not normalized type name, please call qRegisterMetaType instead. QMetaMethod::Access QMetaMethod:: access const. See also convert(). ICS ICS. Writes value as the property's value to the given gadget. The key bit here is that the handle. In general, you only need Q_DECLARE_METATYPE (). Improve this answer. I guess it's the qRegisterMetaType () call itself that's missing. Detailed Description#. Use Q_DECLARE_OPAQUE_POINTER () to be able to register pointers to forward. 就是说 类实列化一次，QML中可以直接使用这个类。. QWidget): def __init__(self):. Pyqt is nothing more than a "translation" from the Qt library (written in C++) to Python, and as this library functions within an object-oriented paradigm, Python code must also be written that way, with widgets represented. I can override QObject's. metaObject()->method(functionIndex); qDebug() << mm. ;. 9k 13 13 gold badges 106 106 silver badges 138 138 bronze badges. Use it if you want to use it as a global enumerator and then you need to call the meta-type runtime registration from the library, not from the application. QObject::connect: Cannot queue arguments of type 'SomeUserDefinedType' (Make sure 'SomeUserDefinedType' is registered using qRegisterMetaType(). When these files are processed by repc, repc generates both Source and Replica header files. {. complains that the metatype isn't registered. So in both cases qRegisterMetaType isn't required for the slot to be called and the custom type to be accessible within the slot (i. Hi Gabriel, good that my answer was helpful :) you’re right, basically the entire Pyqt library will only work within classes. In both. The Qt Meta-Object System in Qt is responsible for the signals and slots inter-object communication mechanism, runtime type information, and the Qt property system. Even though we do not intend to use the type with QVariant in this example, it is good practice to also declare the new type with Q_DECLARE_METATYPE (). Note that the signal has to be in normalized form, as returned by normalizedSignature (). 0. Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. If I register QVector I can't dissconnect this signal and the signal is emited. QObject::connect: Cannot queue arguments of type 'QVector<int>' (Make sure 'QVector<int>' is registered using qRegisterMetaType(). If you only want to store pointer to Foo with the metatype system, then use qRegisterMetaType<Foo *> ();. 二者的联系： QMetaTypeId<TYPE>的类中的成员包含对qRegisterMetaType的调用. 错误原因. It contains a bin folder with the exe file and batch launchers, an include folder with the headers, a source folder with the source files and the moc file (cpp). That is, only Predefined C++ Types and custom objects that have Q_PROPERTY declarations could access from QML environment. e. 1、自定MyDataType 类型，在这个类型的顶部包含：#include <QMetaType>. It is. In QML, the meta-type system is the only way that QML engine can access C++ structures from a QML environment. You can use Qt's typedef for unsigned char: quint8 and you don't need to register it. Call qRegisterMetaType() to make types available to non-template based functions, such as the queued signal and slot connections. 12. I have no problem with registering and using C++ enums in QML code. I'll take your word on that, because on my rig fixing the return type of area() and providing the empty template parameter list for the specialization leaves only get() failing to compile, and as near as I can tell it may be because of the order this was pasted into the question. The registrations must have happened after doing a foo::FooUsingClass *f = new foo::FooUsingClass();. The compound types are then created by association of one or more of the primitive types in arrays, dictionaries or structures. Detailed Description. Since you're passing the parameter via a pointer you don't need to register the type AFAIK. ", which suggests it is only for classes and structs. Handler. ) 1 stopped. 31. ) I register my class like this after it's declaration: Q_DECLARE_METATYPE(taservices::ProcessHandle*); I also added this static method which I call from constructor: QObject::connect: Cannot queue arguments of type 'QProcess::ProcessError' (Make sure 'QProcess::ProcessError' is registered using qRegisterMetaType(). Qt::QueuedConnection，则会发送一个QEvent，并在应用程序进入主事件循环后立即调用该成员。. Can you show the code that's actually causing the error? The. When a new folder is selected I load the thumbnails and. This requires the exchanged data to be of a type that is recognizable by the engine. get (), &senderObject::signal, this, [this] (int int_val, std::string str_value) {function (int_val,str_value)}); Maybe there is an overload template. 2、使用 qRegisterMetaType，将对象注册为元类型 使用qRegisterMetaType对自. #include<QMetaType> typedef QList<int> IntList; qRegisterMetaType<IntList> ("IntList"); error C2909: 'qRegisterMetaType': explicit. To use the enum, you have to explicitly include the full. Asking for help, clarification, or responding to other answers. Call qRegisterMetaType() to make types available to non-template based functions, such as the queued signal and slot connections. metaObject()->indexOfSlot("testFunc ()"); QMetaMethod mm = win. qRegisterMetaType 将某类型注册中 MetaType 系统中. You have to register your custom type for queued signals because by registering it, Qt can make a copy of it in its event loop (which certainly uses QVariant) and pass it as argument later (when the original passed value is long since out. I have gave you below the basic process for a deletion for example. qRegisterMetaType<QAbstractSocket::SocketState>(); Share. cpp is void test (const Person* p)) qrc:example. Since Qt 5. This property holds the state (high or low) of the line signal DTR. I explicitly don't want to update it on every change to one of the quantities, so they don't. ) This is hard to track, so I would. Currently I have a 2d array which represents the game board. You'll need Q_DECLARE_METATYPE () if you want to store your type within a QVariant and you will additionally need qRegisterMetaType<> () if you want to dynamically create and destroy objects of that type at runtime, mostly for queued signal and slots connections or the QObject property system. Type names can be registered with QMetaType by using either qRegisterMetaType () or registerType (). bool QAbstractItemModel:: insertColumn ( int column, const QModelIndex & parent = QModelIndex ()) Inserts a single column before the given column in the child items of the parent specified. I read on documentation that Q_DECLARE_METATYPE makes available type to QVariant, for example (I got it from documentation): @ struct MyStruct { int i;. If you want to pass IBase * between different threads, you need to register class with qRegisterMetaType<IBase *> () call; It is bad practice to pass pointers throught singals, because it is hard to control lifetime of passed objects. 3. Your uint8_t is atomic and you don't need to register it, just use. Even if it works now, it may fail with new Qt versions. If you need a socket, you have two options: Instantiate QTcpSocket or QUdpSocket. When data values are exchanged between QML and C++, they are converted by the QML engine to have the correct data types as appropriate for use in QML or C++. qmlRegisterType makes the QObject (MyClass) class accessible in QML (Q_PROPERTY, Q_ENUM, Q_SIGNAL, Q_SLOT, Q_INVOKABLE, etc. A more complex program sending QSharePointer objects using slots has a similar situation with GDB, that can be reproduced with the previous example. ); RealTimeHistogram: the main widget, a user interface; DataGeneratorThread class DataGeneratorThread. Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. . on_click. That always worked in Qt4, but in Qt5 I get the following error: @error: specializing member ‘::qRegisterMetaType’ requires ‘template<>’ syntax@ qRegisterMetaType("Subclass") also doesn't workI am using ubuntu 16. From the QVariant::operator== documentation. There's no compile time error, but when I run. Follow answered Sep 16, 2014 at 4:21. flush ( self) This function writes as much as possible from the internal write buffer to the socket, without blocking. 2. When data values are exchanged between QML and C++, they are converted by the QML engine to have the correct data types as appropriate for use in QML or C++. I got confused by the documentation and I declared my typedef on line 10 and then I put qRegisterMetaType<AvailablePorts>("AvailablePorts") on line 11. Registering a metatype shouldn't prevent you from disconnecting a signal. Without this binding click will result in no action. You can define one with the enum keyword. Share. This replaces the now-deprecated Q_ENUMS and will automatically register the metatype. Detailed Description. Put a <code>static MetaTypeRegistration<YourType> registration;</code> in the <code>. You only. Teams. In general, you only need Q_DECLARE_METATYPE (). Make sure you call it from within a method. (Make sure 'QModelIndex' is registed using qRegisterMetaType(). The central feature in this model is a very powerful mechanism for seamless object communication called signals and slots . Doc states:. Share. There is a name index for fast lookup of the meta type id. Qt also has a macro Q_DECLARE_METATYPE, which is expanded and specialized in the class QMetaTypeId. More frustrating is I've found PySide documentation alluding to the use of qRegisterMetaType, but I can't find out where to call it from. h file. 12. setContextProperty : Use setContextProperty, When you want to use a single global class to access to or from QML. ui). QChildEvent. An alternative would be to wrap shared_ptr<int> in your own class and implement comparison the way you want. As you have already found out, you must use Q_DECLARE_METATYPE to make the type known to Qt. If you wanted to user the new-style signals, then it would look more like: class TwitterThread (QThread): newStatuses = pyqtSignal (object). So unless you're deliberately creating a typedef registration (and even inThe QObject-based version has the same internal state, and provides public methods to access the state, but in addition it has support for component programming using signals and slots. Where: before using any of the above. 9 under OSX 10. See also insertColumns (), insertRow (), and removeColumn (). QObject::connect: Cannot queue arguments of type 'QVector<QVector<int> >'. py that implements a customwidget class it would look something like: from customwidgetscript import customwidget. qRegisterMetaTypeしているにもかかわらずQObject::connectでランタイムエラーが出る場合の回避策. Sorted by: 5. (Make sure 'QVector<int>' is registered using qRegisterMetaType(). So using qRegisterMetaType () you will just trade Q_ENUM () for Q_DECLARE_METATYPE (). If it is a partial specialization it might be template<class X> instead. h. 1 Answer. qRegisterMetaType<QSqlDatabase>("QSqlDatabase"); Just changing the signal to this form: void dbConnected(QSqlDatabase *db); And, in the slot side I'll use something like this: void onDBConnected(QSqlDatabase * const db); I'm concerned with the usage of db (as in the beginning I've made the reference const), so I make it const here. This way your metatype will be registered once at startup, and the registration is close by the implementation and does not require to modify <code>main</code>. Data Type Conversion Between QML and C++. I can confirm the observed behaviour. struct StandardData { int EmpId; QString Name; }; Q_DECLARE_METATYPE (StandardData) Additionally, you might need to call qRegisterMetaType. 5. cpp 0: 142: 143: If c MyStruct is in a namespace, the Q_DECLARE_METATYPE() macro: 144: has to be outside the namespace: 145: 146adam-iris modified the milestone: Beta Release Aug 25, 2017. Thanks a lot for that!. ) I have Googled for eons trying to figure out a way how to use the qRegisterMetaType() in PySide, to no avail. ) Run a loop on your C++ list and call the append function of qml to add all that data into qml list as well. QtのAPIのドキュメントに、thread-safeと書いてない限りは、QMutex等を使って自分で排他をする必要がある。. Detailed Description. I am also using some in queued signal and slot connections. QtGui. QVariants are important in QML because they used to store the arguments from signals and slots, and also get values from the QMetaProperty system.