from PyQt5 import QtWidgets,QtCore
from untitled import Ui_Form
import  time
  
class MyWindow(QtWidgets.QWidget,Ui_Form):
    _signal=QtCore.pyqtSignal(str) #定义信号,定义参数为str类型
    def __init__(self):  
        super(MyWindow,self).__init__()
        self.setupUi(self)
        self.myButton.clicked.connect(self.myPrint)# 按下按钮执行myPrint
        self._signal.connect(self.mySignal) #将信号连接到函数mySignal
 
    def myPrint(self):
        self.tb.setText("")
        self.tb.append("正在打印，请稍候")
        self._signal.emit("打印结束了吗")# 信号被触发
    def mySignal(self,string):
        print(string)
        self.tb.append("打印结束")
 
if __name__=="__main__":  
    # 以下代码作用为展现ui界面
    import sys  
  
    app=QtWidgets.QApplication(sys.argv)  
    myshow=MyWindow()
    myshow.show()  
    sys.exit(app.exec_())

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys
from datetime import datetime
 
class WinTimer(QWidget):
    def __init__(self,parent=None):
        super(WinTimer,self).__init__(parent)
 
        ###界面显示
        self.label_start=QLabel("开始时间:")
        self.label_curr=QLabel("当前时间:")
        self.label_total=QLabel("时间总计:")
        self.startBtn=QPushButton("开始")
        self.endBtn=QPushButton("停止")
        self.endBtn.setEnabled(False)
 
        ##时间变量
        self.start_time=QDateTime.currentDateTime()
        self.stop_time = QDateTime.currentDateTime()
 
        ###定时器
        self.timer=QTimer()
        self.timer.timeout.connect(self.currTime)
 
        layout=QGridLayout()
        layout.addWidget(self.label_start,0,0,1,2)
        layout.addWidget(self.label_curr, 1,0,1,2)
        layout.addWidget(self.label_total, 2,0,1,2)
        layout.addWidget(self.startBtn, 3, 0)
        layout.addWidget(self.endBtn, 3, 1)
        self.setLayout(layout)
 
        self.startBtn.clicked.connect(self.startTimer)
        self.endBtn.clicked.connect(self.endTimer)
 
        self.setWindowTitle("QTimer")
        self.resize(250,100)
 
    def currTime(self):
        self.stop_time=QDateTime.currentDateTime()
        str_time = self.stop_time.toString("yyyy-MM-dd hh:mm:ss dddd")
        self.label_curr.setText("当前时间:"+str_time)
        
        str_start = self.start_time.toString("yyyy-MM-dd hh:mm:ss")
        str_curr = self.stop_time.toString("yyyy-MM-dd hh:mm:ss")
        startTime = datetime.strptime(str_start, "%Y-%m-%d %H:%M:%S")
        endTime = datetime.strptime(str_curr, "%Y-%m-%d %H:%M:%S")
        seconds = (endTime - startTime).seconds
        self.label_total.setText("时间总计:" + str(seconds)+"s")
 
    def startTimer(self):
        self.start_time = QDateTime.currentDateTime()
        str_time = self.start_time.toString("yyyy-MM-dd hh:mm:ss dddd")
        self.label_start.setText("开始时间:" + str_time)
        self.timer.start(1000)
        self.startBtn.setEnabled(False)
        self.endBtn.setEnabled(True)
 
    def endTimer(self):
        self.timer.stop()
        self.startBtn.setEnabled(True)
        self.endBtn.setEnabled(False)
 
if __name__=="__main__":
    app=QApplication(sys.argv)
    form=WinTimer()
    form.show()

# coding=utf-8 
__author__ = 'a359680405' 
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import * 
global sec 
sec=0
class WorkThread(QThread): 
  trigger = pyqtSignal() 
  def __int__(self): 
    super(WorkThread,self).__init__() 
  
  def run(self): 
    for i in range(203300030): 
      pass
    self.trigger.emit()     #循环完毕后发出信号 
  
def countTime(): 
  global sec 
  sec+=1
  lcdNumber.display(sec)     #LED显示数字+1 
  
def work(): 
  timer.start(1000)        #计时器每秒计数 
  workThread.start()       #计时开始 
  workThread.trigger.connect(timeStop)  #当获得循环完毕的信号时，停止计数 
  
def timeStop(): 
  timer.stop() 
  print("运行结束用时",lcdNumber.value()) 
  global sec 
  sec=0 
app=QApplication([]) 
top=QWidget() 
layout=QVBoxLayout(top)       #垂直布局类QVBoxLayout； 
lcdNumber=QLCDNumber()       #加个显示屏 
layout.addWidget(lcdNumber) 
button=QPushButton("测试") 
layout.addWidget(button)  
timer=QTimer() 
workThread=WorkThread() 
button.clicked.connect(work) 
timer.timeout.connect(countTime)   #每次计时结束，触发setTime  
top.show() 
app.exec()