PyQt:从GUI向线程发送信息

Question

我的HMI由2个按钮组成:启动和停止,还有一个字段QStatusBar,用于将信息从线程打印到GUI.当我"启动"时,我启动一个可以用Stop按钮中断的线程.我想要做的是在线程中的某个点打开一个弹出窗口,以便在线程暂停时为用户提供选择.

from PyQt4 import QtCore, QtGui
import sys
import os
import time
from PyQt4.QtGui import QApplication, QDialog, QListWidgetItem, QListWidget, QIcon
from test_bench_tool2 import Ui_MainWindow
from popup import Ui_popup

"""Class poppup window(continue/quit)"""
class MyPopup(QtGui.QDialog):
    def __init__(self,type):
        super(MyPopup, self).__init__()
        self.res = 0
        self.type=type
        self.ui = Ui_popup()
        self.ui.setupUi(self)
        QtCore.QObject.connect(self.ui.Quit,QtCore.SIGNAL("clicked()"),self.showDialogstop)
       QtCore.QObject.connect(self.ui.Continue,QtCore.SIGNAL("clicked()"),self.showDialogcontinue)

    def showDialogcontinue(self):
        self.res=1
        self.close()
    def showDialogstop(self):
        self.res=0
        self.close()


class MyThread(QtCore.QThread):
    Statuschanged = QtCore.pyqtSignal(str)
    popupmodechanged = QtCore.pyqtSignal(str)
    def __init__(self, parent=None):
        super(MyThread, self).__init__(parent=parent)
        self.Status_auto = ''
        self.dialog = MyPopup('toto')
        self.Status_auto +=''
        self.popup=''
        self.answer=''

    def run(self):
        result = self.get_result()

    def get_result(self, ):
        empty_result = []
        self.popup='Vn'
        self.popupmodechanged.emit((self.popup))
        self.Status_auto +='\n\nMeasures finished!!'
        self.Statuschanged.emit((self.Status_auto))
        results=[]
        #do things to calculate results
        return(results)


class Main(QtGui.QDialog):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        # Connect the Buttons
        QtCore.QObject.connect(self.ui.Start,QtCore.SIGNAL("clicked()"),self.Start)
        QtCore.QObject.connect(self.ui.Stop,QtCore.SIGNAL("clicked()"),self.Stop)
        self.__thread = MyThread(self)
        self.__thread.Statuschanged.connect(self.ui.report_auto.setText)
        self.__thread.popupmodechanged.connect(self.open_popup)

    def open_popup(self):
        self.__thread.dialog.__init__(self.__thread.dialog.type)
        self.__thread.dialog.exec_()

    def Start(self):
        global tableRx, tableTx
        self.ui.report_auto.setText('test in process...')
        self.__thread.start()

    def  Stop(self):
        self.ui.report_auto.setText('test canceled')
        if self.__thread.isRunning():
            self.__thread.terminate()

def main():

    app = QtGui.QApplication(sys.argv)
    window = Main()

    window.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    main()

如何从弹出窗口中获取选择结果以继续线程？我试图将get_result()函数放入这样的测试中

if self.dialog.res == 1:
            print "continue"
            self.dialog.close()
            #do things
        else:
            self.dialog.close()

但是我无法从GUI获得结果到线程.如何从GUI获取信息到我的线程？我有tu使用队列？

Answer 1

根据我的经验,队列是最好的解决方案.这是一种在线程之间共享信息的线程安全方法.您应该在Main类中实例化队列,并将其作为init参数传递给线程:

#MyThread init
def __init__(self, queue, parent=None):
    #the input queue
    self.in_queue = queue 
    #flag indicating if the thread's run function should actually run
    self.running = True 
    super(MyThread, self).__init__(parent=parent)
    self.Status_auto = ''
    self.dialog = MyPopup('toto')
    self.Status_auto +=''
    self.popup=''
    self.answer=''

使用队列,您的线程工作器函数应如下所示:

def run(self)
    while self.running: #to keep the thread running
        if not self.in_queue.empty():
            msg = self.in_queue.get()
            #do something according to the message
        else:
            #do regular operation

这也允许您在消息队列中放置(使用self.queue.put(value))'STOP'消息或其他内容.请注意,在这种情况下,队列的get方法会阻塞线程,直到它实际上可以从队列中获取某些内容(因此if).您可以更改此行为:

msg = self.in_queue.get(block = False)

这样,如果队列是empy,Empty则会引发异常.

要访问Queue类:

from queue import Queue
queue = Queue()

您可以将对话框中的信号连接到线程中的事件处理程序,而不是上面的解决方案,但我没有尝试过这种方式,也不确定它是否能够正常工作.

我希望这能解决你的问题.

干杯,Mátyás