在PyQT中使用QThread进行串行通信(带有p​​yserial)

0la*_*laf 5 python qt pyqt pyserial qthread

关于GUI编程,我几乎是一个初学者。我将QT与python绑定(PyQT4)结合使用。

我正在尝试做的是:

  • 设置一个QThread使用pyserial读取和写入串行端口的端口。
  • 主应用程序应该能够通过运行中的信号发出新的串行数据QThread。并通过QThread信号从接收串行数据 。

我基于此代码(Link)开始了自己的测试实现。在此之前,我阅读了有关QThread的基础知识,并试图了解如何使用它们。以下测试代码是我提出的。对不起,我试图将其保持在最低水平,但仍然是75行代码:

from PyQt4 import QtCore, QtGui
import time
import sys

class SerialData(QtCore.QObject):
    def __init__(self, message):
        super(SerialData, self).__init__()
        self.__m = message
    def getMsg(self):
        return self.__m

class SerialCon(QtCore.QObject):

    finished = QtCore.pyqtSignal()
    received = QtCore.pyqtSignal(SerialData)

    def init(self):
       super(SerialCon, self).__init__()
       # TODO setup serial connection:
       # setting up a timer to check periodically for new received serial data
       self.timer = QtCore.QTimer()
       self.timer.setInterval(400)
       self.timer.timeout.connect(self.readData)
       self.timer.start(200)
       # self.finished.emit()

    def readData(self):
       self.received.emit(SerialData("New serial data!"))
       print "-> serial.readLine() ..."

    @QtCore.pyqtSlot(SerialData)
    def writeData(self, data):
       print "-> serial.write(), ", data.getMsg()


class MyGui(QtGui.QWidget):
    serialWrite = QtCore.pyqtSignal(SerialData)

    def __init__(self):
       super(MyGui, self).__init__()
       self.initUI()

    def initUI(self):
       bSend = QtGui.QPushButton("Send",self)
       bSend.clicked.connect(self.sendData)
       self.show()

    @QtCore.pyqtSlot(SerialData)
    def updateData(self, data):
        print "Gui:", data.getMsg()

    def sendData(self, pressed):
       data = SerialData("Send me!")
       self.serialWrite.emit(data)

def usingMoveToThread():
    app = QtGui.QApplication(sys.argv)
    guui = MyGui()

    thread = QtCore.QThread()
    serialc = SerialCon()
    serialc.moveToThread(thread)

    # connecting signals to slots
    serialc.finished.connect(thread.quit)
    guui.serialWrite.connect(serialc.writeData)
    serialc.received.connect(guui.updateData)
    thread.started.connect(serialc.init)
    thread.finished.connect(app.exit)
    thread.start()

    sys.exit(app.exec_())

if __name__ == "__main__":
    usingMoveToThread()
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我的问题:

  • 在测试代​​码中,从SerialCon对象发出的信号(已移至QThread)似乎未被相应的插槽(MyGuiupdateData)接收到

  • 迟早运行的测试代码总是导致出现Segmentation fault (core dumped)。这使我相信自己错过了一些重要的环节。

是什么原因造成的?

也许我采用了完全错误的方法?-因此,如果您有更好的主意如何实现这一目标,我将不胜感激!

非常感谢!

0la*_*laf 2

起初,我只关注新方法,即自 QT4 ( LinkQThreads )以来应该如何使用,通过创建一个,然后调用,非常像我的第一个代码示例(至少我是这么理解的)。然而我只是不明白为什么我无法将信号从 主应用程序传递。QObjectmoveToThread()QThread

由于我确实需要快速解决我的问题,因此我拼命尝试各种方法。这是第二个代码,它似乎确实按照我想要的方式工作:

from PyQt4 import QtCore, QtGui
import time
import sys
import math


class SerialCon(QtCore.QThread):

    received = QtCore.pyqtSignal(object)

    def __init__(self, parent=None):
        QtCore.QThread.__init__(self)
        # specify thread context for signals and slots:
        # test: comment following line, and run again
        self.moveToThread(self)
        # timer:
        self.timer = QtCore.QTimer()
        self.timer.moveToThread(self)
        self.timer.setInterval(800)
        self.timer.timeout.connect(self.readData)

    def run(self):
        self.timer.start()
        #start eventloop
        self.exec_()

    def readData(self):
        # keeping the thread busy
        # figure out if the GUI remains responsive (should be running on a different thread)
        result = []
        for i in range(1,1000000):
            result.append(math.pow(i,0.2)*math.pow(i,0.1)*math.pow(i,0.3))
        #
        self.received.emit("New serial data!")

    @QtCore.pyqtSlot(object)
    def writeData(self, data):
       #print(self.currentThreadId())
       print(data)

class MyGui(QtGui.QWidget):
    serialWrite = QtCore.pyqtSignal(object)

    def __init__(self, app, parent=None):
       self.app = app
       super(MyGui, self).__init__(parent)
       self.initUI()

    def initUI(self):
       self.bSend = QtGui.QPushButton("Send",self)
       self.bSend.clicked.connect(self.sendData)
       self.show()
    def closeEvent(self, event):
        print("Close.")
        self.serialc.quit();

    @QtCore.pyqtSlot(object)
    def updateData(self, data):
        print(data)

    def sendData(self, pressed):
       self.serialWrite.emit("Send Me! Please?")

    def usingMoveToThread(self):
        self.serialc = SerialCon()
        # binding signals:
        self.serialc.received.connect(self.updateData)
        self.serialWrite.connect(self.serialc.writeData)
        # start thread
        self.serialc.start()

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    guui = MyGui(app)
    guui.usingMoveToThread()
    sys.exit(app.exec_())
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我目前认为这是一种解决方法,但它并不能真正回答我的问题。另外,正如之前链接的 QT 博客条目中提到的,这并不是真正使用QThread. 所以我仍然想知道如何让我的问题中的第一个代码按预期工作。如果您对我的第一个代码有什么问题有任何想法,请告诉我!