pyqt4 多线程定时器为什么没起效 [复制链接]

我用pyqt4做了个界面，两个label（label和label1），程序目的：点击start按钮，第一个label上会交替显示图片，用定时器来实现，第二个label1用了多线程的办法，点击mythread按钮，也想让它用定时器实现图片的交替显示，但没成功，反应都没有，为什么主线程里可以用定时器，自己创建的线程里(红色部分)为什么不能用定时器，请指教，谢谢！

# -*- coding: utf-8 -*-
from PyQt4.QtGui import QApplication, QLabel, QMovie, QPainter, QFontMetrics,QPixmap

import time


from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)



class Ui_Dialog(object):
    def __init__(self):
        #super(Ui_Dialog, self).__init__()
        self.m=QPixmap("I:/python/icon/shuijing/039/yellow.png")
        self.x=QPixmap("I:/python/icon/shuijing/039/yellow.png")
        self.thread = MyThread()
        self.thread.trigger.connect(self.Lable1Show)


    def setupUi(self, Dialog):

        Dialog.setObjectName(_fromUtf8("Dialog"))
        Dialog.resize(700, 600)
        self.label = QLabel(Dialog)
        self.label.setGeometry(QtCore.QRect(80, 50, 200, 200))
        self.label.setObjectName(_fromUtf8("label"))
        self.label1 = QLabel(Dialog)
        self.label1.setGeometry(QtCore.QRect(280, 50, 200, 200))
        self.label1.setObjectName(_fromUtf8("label1"))
        self.pushButton = QtGui.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(170, 300, 191, 61))
        self.pushButton.setText('Stop')
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.pushButton2 = QtGui.QPushButton(Dialog)
        self.pushButton2.setGeometry(QtCore.QRect(170, 400, 191, 61))
        self.pushButton2.setText('myThread')
        self.pushButton2.setObjectName(_fromUtf8("pushButton2"))
        self.pushButton3 = QtGui.QPushButton(Dialog)
        self.pushButton3.setGeometry(QtCore.QRect(170, 500, 191, 61))
        self.pushButton3.setText('start')
        self.pushButton3.setObjectName(_fromUtf8("pushButton3"))
        QtCore.QObject.connect(self.pushButton, QtCore.SIGNAL(_fromUtf8("clicked()")),self.stop1)
        QtCore.QObject.connect(self.pushButton2, QtCore.SIGNAL(_fromUtf8("clicked()")),self.myThread)
        QtCore.QObject.connect(self.pushButton3, QtCore.SIGNAL(_fromUtf8("clicked()")),self.start)
        #QtCore.QObject.connect(self.pushButton2, QtCore.SIGNAL(_fromUtf8("clicked()")),self.changePic2)

        #self.label.setMovie(self.m)
        self.label.setScaledContents(True)
        self.label.setPixmap(self.m)
        self.label1.setScaledContents(True)
        self.label1.setPixmap(self.x)

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def start(self):
        self.timer=QtCore.QTimer()
        self.timer.setInterval(500)
        self.timer.start()
        QtCore.QObject.connect(self.timer,QtCore.SIGNAL("timeout()"),self.timeOut)

    global num
    num=0  
    def timeOut(self):
        global num
        #num=num+1        
        num=num+1
        if (num%2==0):
             self.b=QPixmap("I:/python/icon/shuijing/039/red.png")
             self.label.setScaledContents(True)
             self.label.setPixmap(self.b)
             self.label.repaint()

        else:
             self.b=QPixmap("I:/python/icon/shuijing/039/green.png")
             self.label.setScaledContents(True)
             self.label.setPixmap(self.b)
             self.label.repaint()

    def myThread(self):

        self.thread.start()


    def Lable1Show(self,str1):

             #self.b=QPixmap("I:/python/icon/shuijing/039/red.png")
             self.h=QPixmap(str1)
             self.label1.setScaledContents(True)
             self.label1.setPixmap(self.h)
             self.label1.repaint()

    def stop1(self):
        #flag=0
        self.timer.stop()
        self.b=QPixmap("I:/python/icon/shuijing/039/green.png")
        self.label.setScaledContents(True)
        self.label.setPixmap(self.b)
        self.thread.terminate()

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(_translate("Dialog", "Dialog", None))

class MyThread(QtCore.QThread):
    trigger = QtCore.pyqtSignal(str)

    def __init__(self,parent=None):  
        super(MyThread, self).__init__(parent)

   def run(self):
        # your task code
        while True:
            self.timer2=QtCore.QTimer()
            self.timer2.setInterval(500)
            self.timer2.start()
            QtCore.QObject.connect(self.timer2,QtCore.SIGNAL("timeout()"),self.timeOut2)

    def timeOut2(self):
        num=0
        while True:
            num += 1
            if (num%2==0):
                self.trigger.emit("I:/python/icon/shuijing/039/red.png")
            else:
                self.trigger.emit("I:/python/icon/shuijing/039/grey.png")
                #time.sleep(1)
def main():

    app = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    import sys

    main()