qregistermetatype. 12. qregistermetatype

(Parent is QTcpSocket (0x24a6ce8), parent's thread is ServiceSlots. QMetaType Synopsis Functions def __eq__ (b). No, everything is in separated folders. ros. Re: Q_DECLARE_METATYPE vs qRegisterMetaType for non global namespace classes (QTest) The reason for this behavior might be caused by the fact that runtime signal/slot connections are checked by string manipulation - both Q_DECLARE_METATYPE, SIGNAL, SLOT macros and 'moc' are (among other things) converting type-names to text and pass it along. Usually, I do this type of updates using signals and slots, but the run function is not PyQt specific. In general, you only need Q_DECLARE_METATYPE (). In variant 1 the call is invoked immediately like in direct connection. I can override QObject's. If you only want to store pointer to Foo with the metatype system, then use qRegisterMetaType<Foo *> ();. The following code allocates and destructs an instance of MyClass: Type names can be registered with QMetaType by using either qRegisterMetaType() or registerType(). 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. QObject::connect: Cannot queue arguments of type 'QVector<int>'. The QML engine provides built-in support for a large number. To make the diagnosis of test failures easier, the results of. on_click) binds signal of a button (clicked) to a slot self. The QML engine provides built-in support for a. #pragma once #include <QObject> class MyClass : public QObject { Q_OBJECT public: static void initQML (); MyClass (); MyClass (const MyClass &myClass. You need to (or at least this is how it works for me) create a signal that will be emitted every iteration of the for loop in your thread. Appears to the right of the line. This replaces the now-deprecated Q_ENUMS and will automatically register the metatype. Adding a Q_DECLARE_METATYPE() makes the type known to all template based functions, including QVariant. ) QObject: Cannot create children for a parent that is in a different thread. There is a name index for fast lookup of the meta type id. @SGaist Yes, I am using it with QVariant, mostly with QSettings to save and retrieve data easily by overriding QDataStream operators. ) 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. The default value is Data8, i. ) QObject: Cannot create children for a parent that is in a different thread. QObject. Detailed Description. Use Q_DECLARE_METATYPE (std::string) in one of your headers. So I don't stream the pointer itself just copy the properties and set them to a new created pointer object. It seems QVariant is not direct part of queued connections mechanism. 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. I have tried registering QTextCursor with qRegisterMetaType, but it doesn't help; Anyone can tell what I am doing wrong, and how to fix that? Many thanks. launch, the quads in rviz cannot detect the enviroment and it shows QObject::connect: Cannot queue arguments of type 'QVector' (Make sure 'QVector' is registered using qRegisterMetaType(). The connection in question is queued. #include <QObject> #include <QVariant> class Record : public QPair<qreal, qreal> {. Returns the internal ID used by QMetaType. (Make sure 'QTextBlock' is registered using qRegisterMetaType (). The factory must be set before executing the engine. 1. A QItemSelection is basically a list of selection ranges, see QItemSelectionRange. Save yourself the hassle and use QStringList. ) QObject::connect: Cannot queue arguments of type 'QList' (Make sure 'QList' is registered using qRegisterMetaType(). I have gave you below the basic process for a deletion for example. QChildEvent. QMetaType:: Q_DECLARE_OPAQUE_POINTER (PointerType) This macro enables pointers to forward-declared types (PointerType) to be registered with QMetaType using either Q_DECLARE_METATYPE() or qRegisterMetaType(). . The. Re: How to use Q_DECLARE_METATYPE. Consider the specific case of qRegisterMetaType. rows += self. bool QMetaProperty:: writeOnGadget ( void * gadget, const QVariant & value) const. 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. 31. (Make sure. 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. setContextProperty qmlRegisterType qRegisterMetaType等区别. Normally it's done directly in the main () How: Just call qRegisterMetaType<QMap<QString,long long unsigned int> > (); It doesn't matter how you refer to MyClass in the template argument. A QItemSelection describes the items in a model that have been selected by the user. Nejat Nejat. In conclusion: Don't use Q_DECLARE_METATYPE and qRegisterMetaType for your QObject enum. Any ideas? Nope, registering with qRegisterMetaType<std::vector<int>>() has same effect as not registering at all (using QVector<int> works without registration, but does not expose length, either). Data Type Conversion Between QML and C++. Hey Something I wanted to follow up as I noticed I'm not the only with the issue. A common way to register the type is in main or with a static function register. The signature of your signal does not match the signature of what you wrote in the SIGNAL macro -- those are non-const references:. emit (foo_text) def settext ( self, text ): print (text) Im sure you guys get this alot but im trying to thread and im getting this error: (Parent is QTextDocument (0x1243bfd4290), parent's thread is QThread (0x12437dd1260), current thread is. Call qRegisterMetaType () to make type available to non-template based. The following code allocates and destructs an instance of MyClass: 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. Any class or struct that has a public default constructor, a public copy constructor , and a. This maybe is not the nicest solution, but it works just fine: Add a property to the wizardpage which contains the QListView and let it return the pointer to the selectionmodel. pro file: CONFIG += qmltypes. Doc states:. しかし、Qtを使っている場合は、わざわざ自分でMutexの管理をしなくても、スレッドとのデータのやり取りを全て signal/slotでやってしまい、共有データを. Returns a list of child objects. 1. To not see the message. The QItemSelection class is one of the Model/View Classes and is part of Qt’s. 9 under OSX 10. This property holds the state (high or low) of the line signal DTR. QObject::connect: Cannot queue arguments of type 'QModbusDevice::State' (Make sure 'QModbusDevice::State' is registered using qRegisterMetaType (). There is no use case for implementing qRegisterMetaType, because PyObject. [since 6. ) The image I am trying to pass is a cv::Mat which I converted to a QImage which I afterwards converted to a QString. Maybe qRegisterMetaType is what you missed. This function was introduced in Qt 6. 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. Returns the access specification of this method (private, protected, or public). ) This is hard to track, so I would. . When you think about, there are quite convincing reasons to disallow it implicitly happening. In this case, PyQt will just create a new signal type for you on the fly when you emit the signal. If I save the image to disk in the DB thread just after emitting the signal, it is good. ; Create a native socket descriptor, instantiate QAbstractSocket, and call setSocketDescriptor() to wrap the native socket. 2 Answers Sorted by: 3 You do not need to call qRegisterMetaType () to use a type with QVariant. 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. QObject is the heart of the Qt Object Model . ICS ICS. " Currently I have no UI implemented (yet!). Read and abide by the Qt Code of Conduct. 12. If you are using queued connections, you need to register std::string as meta type. The following code allocates and destructs an instance of MyClass:使用Q_DECLARE_METATYPE()可以让这个数据类型T放到QVariant里面。如果想以队列的方式让T使用信号与槽，当第一次连接的时候就要调用qRegisterMetaType<T>()。 QObject::property()要和类型T一起使用，这个时候qRegisterMetaType<T>()要提前调用。This enum specifies how the split () functions should behave with respect to empty strings. . Q_DECLARE_METATYPE is only needed for template-based functions. on_click. 将C++实现的类在QML中调用的. error C2059: syntax error : 'string' warning C4667: 'int qRegisterMetaType (void)' : no function template defined that matches forced. bool QLocalSocket. This implies that you can create bindings that use this property as a dependency or install QPropertyObserver objects on this property. constData ()), " qRegisterNormalizedMetaType ", " qRegisterNormalizedMetaType was called with a not normalized type name, please call qRegisterMetaType instead. I created a. 步骤： (以自定义MyDataType类型为例）. When sender and receiver objects do not live in the same thread, the Qt::QueuedConnection type is used. Any class or struct that has a public default constructor, a public copy constructor and a public destructor can be registered in QMetaType. hskoglund last edited by . This line has disappeared in Qt 5. The following code allocates and destructs an instance of MyClass:The Q_DECLARE_METATYPE() macro and qRegisterMetaType() function documentation contain more detailed information about their uses and limitations. You could try using registerConverter () to allow implicit conversion of the shared_ptr<int> to a regular int, and compare them that way. Toggle Light / Dark / Auto color theme. (Make sure 'QVector<int>' is registered using qRegisterMetaType(). Sets the port on the local side of a connection to port. Can you show the code that's actually causing the error? The. qRegisterMetaType<ProcessHandle*>("ProcessHandle*"); qRegisterMetaType<ProcessHandle*>("ProcessHandle*const"); For the purposes of queuing arguments, const pointer is equal to normal pointer, since it's being copied not changed. The QSignalSpy class provides an elegant mechanism for capturing the list of signals emitted by an object. Follow answered Sep 16, 2014 at 4:21. 12. Every second this 2d array is changed by a thread (representing the passage of time) and then this thread emits a signal telling the main GUI to update based on the new game board. call qRegisterMetaType with the name specified, else reading properties. iv. Note: This function is thread-safe. template<class T> QMetaObject::Connection connect_from_pointer ( const QSharedPointer<T>& sender,. program exits if. If the signal is being emitted, I get this error: @. @reddy9pp said in QObject::connect: Cannot queue arguments of type 'std::string' (Make sure 'std::string' is registered using qRegisterMetaType(). Then, connect this signal to a slot that will do the actual update of the data. しかし、Qtを使っている場合は、わざわざ自分でMutexの管理をしなくても、スレッドとのデータのやり取りを全て signal/slotでやってしまい、共有データを. 1、自定MyDataType 类型，在这个类型的顶部包含：#include <QMetaType>. If you use QMetaObject::invoke you've got an option to choose connection type - Direct or Queued. complains that the metatype isn't registered. Foo and Foo* are different types and need to be registered separately. QtGui import * from PyQt5. )" caused by working in threads. Also you may need to use qRegisterMetaType function. As soon as the first event arrives I got the errormessage: @QObject::connect: Cannot queue arguments of type 'QQuickChangeSet'. Check if from PyQt5. That's not. If you want both, then register both. Use Q_DECLARE_OPAQUE_POINTER () to be able to register pointers to forward. v. I. By implementing a factory it is possible to create custom QNetworkAccessManager with specialized caching, proxy and cookie support. qRegisterMetaType() since the names are resolved at runtime. 步骤： (以自定义MyDataType类型为例）. QMetaType is Qt's way to have run-time dynamic information about your types. When a new folder is selected I load the thumbnails and. I can confirm the observed behaviour. 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. This requires the exchanged data to be of a type that is recognizable by the engine. Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. TheIt is safe to call qRegisterMetaType() more than once. g. – thuga. 0. I realize that this actually works when more than one signal of different types is sent, e. ) I believe this is because I am updating the text box from threads other than the ma. I read on documentation that Q_DECLARE_METATYPE makes available type to QVariant, for example (I got it from documentation): @ struct MyStruct { int i;. Specifically, the function have to be called before using the struct in a queued signal/slot connection or. ) 1 stopped. Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this siteThis macro is used to specialise the template class QMetaTypeId with typename TYPE, in which, a static member function qt_metatype_id () is defined. The stretch factor changes the width of all characters in the font by factor percent. #include<QMetaType> typedef QList<int> IntList; qRegisterMetaType<IntList> ("IntList"); error C2909: 'qRegisterMetaType': explicit. QSignalSpy itself is a list of QVariant lists. ) So it seems to be a multi-threading issue caused by this instruction connect (process,&QProcess::started, [this. QtCore import * from PyQt5. It is. Nejat Nejat. Note: This function is thread-safe. QDBusArgument is the central class in the Qt D-Bus type system, providing functions to marshall and demarshall the primitive types. You can use the tags to annotate your methods. My first intuition was to have a class inheriting from rclcpp::Node only with an instance of MainWindow but didn't manage to have it work that way. Variant 3: use MACRO instead of std::invoke in variant 2. 150%) wider. e. First of all you need to declare your custom object for Qt metatype system. QNativeSocketEngine::write () was not called in QAbstractSocket::ConnectedState. That is, only Predefined C++ Types and custom objects that have Q_PROPERTY declarations could access from QML environment. The Qt doc on qRegisterMetaType explicitly says : T must be declared with Q_DECLARE_METATYPE (). ;. 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. Variant 2: use std::invoke inside a lambda, which is passed to QMetaObject::invoke. You need to create your own factory that will register functors that will call qRegisterMetaType in runtime. (Make sure 'QVector<int>' is. QPainter supports drawing lines, polygons, vector paths, images, and text. QMetaType:: Q_DECLARE_OPAQUE_POINTER (PointerType) This macro enables pointers to forward-declared types (PointerType) to be registered with QMetaType using either Q_DECLARE_METATYPE() or qRegisterMetaType(). main. Hello, Can someone tell me about how to register a metatype in pyqt5. e. For the record your issue come from the fact that Qt preprocessor for signals and slots, the moc, does not use a full-blown C++ parser. – pmf Feb 7, 2019 at 16:35 QObject::connect: Cannot queue arguments of type 'QTextCursor' (Make sure 'QTextCursor' is registered using qRegisterMetaType(). cpp2 Answers. g. (Make sure 'MyStruct' is registered using qRegisterMetaType (). Although you can just create QBluetoothDeviceInfo objects on your own and fill them with data, the easier way is to use the QBluetoothDeviceDiscoveryAgent to start an automated search for visible Bluetooth devices within the connectable range. akshatrai91 7 Jan 2021, 06:21. The custom type T needs to be registered in Qt meta-type system in order to be used in e. To do this you first subclass logging. Share. I am trying to learn Qt and I am attempting to do so by making a little titres game. evaluate("1 + 2"); evaluate () returns a QScriptValue that holds the result of the evaluation. Then you should register your object to use it with QML. Normally you would do this in main () or. Detailed Description. rep file extension, short for Replica. ) When I do . QVariants are important in QML because they used to store the arguments from signals and slots, and also get values from the QMetaProperty system. That always worked in Qt4, but in Qt5 I get the following error: @error: specializing member ‘::qRegisterMetaType<Subclass>’ requires ‘template<>’ syntax@. Hello! connect( threadEstudo, SIGNAL( sinalResultados ( QList<analysis_results>)), this, SLOT( slotAvaliaResultadosEstudo ( QList<analysis_results>))); You may notice that I put the qDebug () so I can check if all metatypes were correctly registered, and the result was. If _message is a string then the slot must have the argument: foo_text = "Foo" self. You can use Qt's typedef for unsigned char: quint8 and you don't need to register it. Finds signal and returns its index; otherwise returns -1. 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. com. The same plugin may be loaded multiple times during the application's lifetime. hi, I always after application running, receive debug text of: QObject::connect: Cannot queue arguments of type 'MyStruct'. OTOH, passing it by value in lambdas too is dangerous and can cause memory leaks. Also note that I have my sig/slots with a reference, but if I used a connect like this: @. 1. answered May 10, 2013 at 2:25. 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++. [since 6. QObject::connect: Cannot queue arguments of type 'object' (Make sure 'object' is registered using qRegisterMetaType(). This event handler can be reimplemented in a subclass to receive child events. (Parent is QTextDocument (0x5a28e48), parent's thread is QThread (0x8dbcc0), current thread is QThread. [override virtual noexcept] QQmlEngine:: ~QQmlEngine Destroys the QQmlEngine. Please visit robotics. My Thread is as. Otherwise, returns QPartialOrdering::Less, QPartialOrdering::Equivalent or QPartialOrdering::Greater if lhs is less than, equivalent to or. So I played around, copied the original macro and adapted it a bit: @. Share. on top of main. an int and a std::string. I tested your code on Qt 5. QObject::connect: Cannot queue arguments of type 'my_enum' (Make sure 'my_enum' is registered using qRegisterMetaType(). 0 BY-SA 版权协议，转载请附上原文出处链接和本声. Adding a Q_DECLARE_METATYPE() makes the type known to all template based functions, including QVariant. One or many threads can block waiting for a QWaitCondition to set a condition with wakeOne() or wakeAll(). 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. py that implements a customwidget class it would look something like: from customwidgetscript import customwidget. Following this logic, the following code may not work: connect (senderObject. The following code: self. Obviously then you would not do registerComparator (). FollowThis can be made to work but it turns out there's a bit of manual labour to be done. So if you put the register in constructor, you have to instance your class once and then make the connection. To register VideoMeta you need to call qRegisterMetaType<VideoMeta>(). In QML, the meta-type system is the only way that QML engine can access C++ structures from a QML environment. Specifically, the function have to be called before using the struct in a queued signal/slot connection or before. Hello, Can someone tell me about how to register a metatype in pyqt5. 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 (). (Make sure 'QVector<int>' is registered using qRegisterMetaType (). Type "MyType" has id: 1024 ; register status: true QObject::connect: Cannot queue arguments of type 'MyType' (Make sure 'MyType' is registered using qRegisterMetaType(). Detailed Description. QObject::connect: Cannot queue arguments of type 'ProcessHandle*const' (Make sure 'ProcessHandle*const' is registered using qRegisterMetaType(). Once the connection object is instantiated, connection->moveToThread (comThread) is called. cpp</code> file implementing <code>YourType</code>. Object::connect: No such slot main_application::input_handler(button_back) Of course, there is, because signature is main_application::input_handler(button_type), and button_back is a value, not type. 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. ) 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. Call qRegisterMetaType() to make types available to non-template based functions, such as the queued signal and slot connections. (Parent is QTcpSocket (0x24a6ce8), parent's thread is ServiceSlots (0xea66488), current thread is QThread (0x2418a78) See also qRegisterMetaType(). In practice, both the Q_DECLARE_METATYPE() macro and the qRegisterMetaType() template function can be used to register custom types, but qRegisterMetaType() is only required if you need to perform. QAbstractSocket is the base class for QTcpSocket and QUdpSocket and contains all common functionality of these two classes. Teams. In general, you only need Q_DECLARE_METATYPE (). MyEnum needs to be registered with qRegisterMetaType. It also reflects the size of the paging file at that time. queued connections. But this is all useless if you are not using templates. Qt 避免使用qRegisterMetaType（指针与引用），关注常量,qt,Qt,发出信号： void dbConnected(const QSqlDatabase &db); 我从中学到了如何避免使用 qRegisterMetaType<QSqlDatabase>("QSqlDatabase"); 在吃角子老虎的那一边，我会用这样的东西： void onDBConnected(QSqlDatabase * const db); 我关心的是db的使用（正. . It enables things such as QVariant wrapping of custom types, copy of queued connection arguments, and more. A QWindow created with the surface type RasterSurface can be used in combination with QBackingStore and QPainter , Qt’s highly optimized 2D vector graphics API. qRegisterMetaType 将某类型注册中 MetaType 系统中. I have no problem with registering and using C++ enums in QML code. For pointer types, it also requires that the pointed to type is fully defined. QObject is the heart of the Qt Object Model. These are the top rated real world C++ (Cpp) examples of qmlRegisterUncreatableMetaObject extracted. new children are appended at. Returns QPartialOrdering::Unordered if comparison is not supported or the values are unordered. Data Type Conversion Between QML and C++. @SGaist if you see the original question I posted the contents of the devicepresence. We have two classes in this example: DataGeneratorThread: is a QThread and is responsible for the actual data generation (generates random numbers according to a gaussian p. ) but does not allow the transmission of data between threads, for this case it must be registered using qRegisterMetaType<MyClass::ErrorCode>("ErrorCode"): main. So you can call it from your constructor. We have a couple projects that we developed using Visual Studios 2017, VisualGDB Vers 5. runBtn = QtWidgets. uint8_t is the typedef for unsigned char . 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 (). One of these plugins uses Q_DECLARE_METATYPE on some types that need to be stored in a QVariant. Hilk. Data Type Conversion Between QML and C++. ) What I have done is, declare in the main the qRegisterMetatype but it still complaining. struct StandardData { int EmpId; QString Name; }; Q_DECLARE_METATYPE (StandardData) Additionally, you might need to call qRegisterMetaType. 15. Notice that with this approach you will only be able to check the value of the passed. Here how connect looks in main constructor: connect (w1, SIGNAL (sentInt (int)), this, SLOT (receiveInt (int))); Such simple app works, but if i change parameters from int to "signed long long" it will give message during runtime and signal won't be emitted: QObject::connect: Cannot queue arguments of type 'signed long long'. For example if you have a customwidgetscript. Here is the list of information kept for each type in the meta-type system: The Type Name as registered. mycompany. 4 x64, and PyQt5 using its binary provided on riverbankcomputiong. Any class or struct that has a public constructor, a public copy constructor, and a public destructor can be registered. Call qRegisterMetaType() to make types available to non-template based functions, such as the queued signal and slot connections. ) QObject: Cannot create children for a parent that is in a different thread. Writes value as the property's value to the given gadget. How to register custom type with QML if it is passed as const from C++. QNetworkAccessManager is used for all network access by QML. Hello, i have the following warning and i would like to ask how can i fix it. See Qt documentation which contains sample code. You only. qmlRegisterUncreatableType# qmlRegisterUncreatableType (pytype: type, uri: str, versionMajor. But the problem comes up when I try to send it to C++ slot, that have my enum as parameter. It will return correct type value like 1230 for type in function SomethingElse of class C. Currently, on Linux and Android it is used for specifying connection to a server listening to a socket bound to an abstract address. For the moment, moc will extract and record all tags, but it will not handle any of them specially. 3. QVariant’s operator== now uses QMetaType::equals for the comparison. (Make sure 'QTextCharFormat' is registered using qRegisterMetaType(). Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. Sep 21, 2015 at 14:17. multithreaded software and I am getting the warning says: (Make sure. f. What worries me is that. when pressButtonThread is triggered: QObject::connect: Cannot queue arguments of type 'QTextBlock'. Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. cpp file. Without this binding click will result in no action. 1 Answer. 用qRegisterMetaType对自定义的类型进行注册，就是为了告诉Qt如何去做这些事情。. This member is allocated and filled with data from a qt slot like so: int channel_count =. Represents a handle to a signal-slot (or signal-functor) connection. Before emitting a signal across a thread boundary with a non-trivial argument type (like QModelIndex ), you must first call this: qRegisterMetaType<QModelIndex> ("QModelIndex"); That prepares Qt to be able to emit the signal across a thread boundary. 在使用 qRegisterMetaType<int>("int&");注册一个自定义类型给线程后，就出现“启动程序失败,路径或者权限错误”的提示，之后程序就一直编译不过去。不管删除了相关的文件后，或者重新构建，都是一样的问题。 但是，在不断的摸索后，突然之间就可以了，后面实验. Note: If you want to use your custom metatypes also in queued slot connections or with QMetaMethod, you have to call qRegisterMetaType<QPushButton*>() Share. g. The entries are addressed via startAddress () and the valueCount () number of contiguous entries. 1 Reply Last reply 0. To avoid never ending notification loops you can temporarily block signals. QtCore. If you need a socket, you have two options: Instantiate QTcpSocket or QUdpSocket. 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. I intially installed a later version of Qt but then reverted back to Version 5. Any class or struct that has a public default constructor, a public copy constructor, and a public destructor can be registered. I had to uninstall it first, then reinstall it: # upgrade pip python3 -m pip install --upgrade pip # uninstall python3 -m pip uninstall PyQt5 python3 -m pip uninstall PyQt5-sip python3 -m pip uninstall PyQtWebEngine # reinstall python3 -m pip install PyQt5 python3. Call qRegisterMetaType() to make types available to non-template based functions, such as the queued signal and slot connections. I realize that this actually works when more than one signal of different types is sent, e. QPushButton(self. So, what is the right way to get rid from: QObject::connect: Cannot queue arguments of type 'QTextCursor' (Make sure 'QTextCursor' is registered using qRegisterMetaType (). e. Now, this simple class holds small samples of. . Q_DECLARE_METATYPE (QSqlRecord) has to be outside any classes and namespaces.