QObject::connect: Cannot queue arguments of type 'QTextCursor'

问题

Im trying to send a signal from a non-main thread in PyQt but i dont know what am doing wrong! And when i execute the program it fails with this error:

QObject::connect: Cannot queue arguments of type 'QTextCursor'
(Make sure 'QTextCursor' is registered using qRegisterMetaType().)

here is my code:

 class Sender(QtCore.QThread):
        def __init__(self,q):
            super(Sender,self).__init__()
            self.q=q
        def run(self):

            while True:
                pass
                try: line = q.get_nowait()
             # or q.get(timeout=.1)
                except Empty: 
                    pass
                else: 
                   self.emit(QtCore.SIGNAL('tri()')) 
 class Workspace(QMainWindow, Ui_MainWindow):
    """ This class is for managing the whole GUI `Workspace'.
        Currently a Workspace is similar to a MainWindow
    """

    def __init__(self):  
try:
            from Queue import Queue, Empty
        except ImportError:
            while True:
    #from queue import Queue, Empty  # python 3.x
                print "error"

        ON_POSIX = 'posix' in sys.builtin_module_names

        def enqueue_output(out, queue):
            for line in iter(out.readline, b''):
                queue.put(line)
            out.close()

        p= Popen(["java -Xmx256m -jar bin/HelloWorld.jar"],cwd=r'/home/karen/sphinx4-1.0beta5-src/sphinx4-1.0beta5/',stdout=PIPE, shell=True, bufsize= 4024)
        q = Queue()
        t = threading.Thread(target=enqueue_output, args=(p.stdout, q)) 
          t.daemon = True # thread dies with the program
        t.start()
        self.sender= Sender(q)
         self.connect(self.sender, QtCore.SIGNAL('tri()'), self.__action_About)
        self.sender.start()

I think that my way of send parameter to the thread is wrong... I need to know how to send parameters to a thread, in my case i need to send q to the worker thread.

回答1:

Make sure 'QTextCursor' is registered using qRegisterMetaType().

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. It associates a type name to a type so that it can be created and destructed dynamically at run-time. Declare new types with Q_DECLARE_METATYPE() to make them available to QVariant and other template-based functions. Call qRegisterMetaType() to make type available to non-template based functions, such as the queued signal and slot connections.

来源：https://stackoverflow.com/questions/13674792/qobjectconnect-cannot-queue-arguments-of-type-qtextcursor

标签

python

multithreading

pyqt4