QTimer、QThread

QTimer显示时间

QTimer

'''

动态显示当前时间

QTimer
QThread

多线程：用于同时完成多个任务




'''

from PyQt5.QtWidgets import QWidget, QPushButton, QApplication, QListWidget, QGridLayout, QLabel
from PyQt5.QtCore import QTimer, QDateTime
import sys


class ShowTime(QWidget):

    def __init__(self, parent=None):
        super(ShowTime, self).__init__(parent)
        self.setWindowTitle("动态显示当前时间")

        self.label = QLabel('显示当前时间')
        self.startBtn = QPushButton('开始')
        self.endBtn = QPushButton('结束')
        layout= QGridLayout()

        self.timer = QTimer()
        self.timer.timeout.connect(self.showTime)

        layout.addWidget(self.label,0,0,1,2)
        layout.addWidget(self.startBtn,1,0)
        layout.addWidget(self.endBtn,1,1)

        self.startBtn.clicked.connect(self.startTimer)
        self.endBtn.clicked.connect(self.endTimer)

        self.setLayout(layout)

    def showTime(self):
        time = QDateTime.currentDateTime()

        timeDisplay = time.toString("yyyy-MM-dd hh:mm:ss dddd")
        self.label.setText(timeDisplay)

    def startTimer(self):
        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 = ShowTime()
    form.show()
    sys.exit(app.exec_())

QTimer让窗口定时关闭

'''

让程序定时关闭

QTimer.singleShot

'''

import sys
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *

if __name__ == '__main__':
    app = QApplication(sys.argv)
    label = QLabel('<font color=red size=140><b>Hello World，窗口在5秒后自动关闭!</b></font>')
    label.setWindowFlags(Qt.SplashScreen | Qt.FramelessWindowHint)
    label.show()
    QTimer.singleShot(5000,app.quit)

    sys.exit(app.exec_())

使用线程类QThread编写计数器

'''

使用线程类（QThread）编写计数器


QThread

def run(self):
   while True:
       self.sleep(1)
       if sec == 5:
           break;

QLCDNumber



WorkThread(QThread)
用到自定义信号

'''

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

sec = 0

class WorkThread(QThread):
    timer = pyqtSignal()   # 每隔1秒发送一次信号
    end = pyqtSignal()     # 计数完成后发送一次信号
    def run(self):
        while True:
            self.sleep(1)  # 休眠1秒
            if sec == 5:
                self.end.emit()   # 发送end信号
                break
            self.timer.emit()   # 发送timer信号

class Counter(QWidget):

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

        self.setWindowTitle("使用线程类（QThread）编写计数器")
        self.resize(300, 120)

        layout = QVBoxLayout()
        self.lcdNumber = QLCDNumber()
        layout.addWidget(self.lcdNumber)

        button = QPushButton('开始计数')
        layout.addWidget(button)

        self.workThread = WorkThread()

        self.workThread.timer.connect(self.countTime)
        self.workThread.end.connect(self.end)
        button.clicked.connect(self.work)

        self.setLayout(layout)

    def countTime(self):
        global sec
        sec += 1
        self.lcdNumber.display(sec)

    def end(self):
        QMessageBox.information(self,'消息','计数结束',QMessageBox.Ok)

    def work(self):
        self.workThread.start()




if __name__ == "__main__":
    app = QApplication(sys.argv)
    form = Counter()
    form.show()
    sys.exit(app.exec_())