Question

尝试构建秒表GUI，但我无法使暂停功能正常工作。每当我暂停计时器然后重新开始时，计时器就会以每秒一秒的速度运行。

import sys
import datetime
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QPushButton, QGridLayout
from PyQt5.QtCore import QTimer, Qt
from PyQt5.QtGui import QFont, QPalette

class StopWatch(QWidget):
    def __init__(self):
        super().__init__()
        self.isRunning = False
        self.counter = 0

        self.setWindowTitle('Stop Watch')
        self.create_layout()

    def create_layout(self):
        self.timer = QTimer()
        self.timer.setInterval(1000)

        labelFormating = QPalette()
        labelFormating.setColor(QPalette.WindowText, Qt.darkBlue)

        self.startButton = QPushButton('Start')
        self.pauseButton = QPushButton('Pause')
        self.stopButton = QPushButton('Stop')

        self.startButton.setEnabled(True)
        self.pauseButton.setEnabled(False)
        self.stopButton.setEnabled(False)

        self.startButton.clicked.connect(self.start_timer)
        self.pauseButton.clicked.connect(self.pause)
        self.stopButton.clicked.connect(self.stop_timer)

        self.displayLabel = QLabel(str(datetime.timedelta(seconds=0)))
        self.displayLabel.setFont(QFont('Open Sans', 24))
        self.displayLabel.setPalette(labelFormating)

        gridLayout = QGridLayout()
        gridLayout.addWidget(self.displayLabel, 0, 0, 1, 3) # row span | color span (extend)
        gridLayout.addWidget(self.startButton,  1, 0, 1, 1)
        gridLayout.addWidget(self.pauseButton,  1, 1, 1, 1)
        gridLayout.addWidget(self.stopButton,   1, 2, 1, 1)
        gridLayout.setAlignment(self.displayLabel, Qt.AlignCenter)
        self.setLayout(gridLayout)

    def start_timer(self, slot):
        print('start clicked')
        self.startButton.setEnabled(False)
        self.pauseButton.setEnabled(True)
        self.stopButton.setEnabled(True)
        self.timer.start()
        self.timer.timeout.connect(self.run) #This signal is emitted when the timer times out.

    def stop_timer(self):
        print('Stop clicked')
        self.startButton.setEnabled(True)
        self.pauseButton.setEnabled(False)
        self.stopButton.setEnabled(False)
        self.isRunning = False
        self.timer.stop()
        self.displayLabel.setText(str(datetime.timedelta(seconds=0)))

    def run(self):
        # print('Counter value', str(self.counter)) 
        self.counter += 1
        self.display()

    def pause(self):
        print('pause clicked')
        self.startButton.setEnabled(True)
        self.pauseButton.setEnabled(False)
        self.stopButton.setEnabled(True)
        self.timer.stop()
        self.displayLabel.setText(str(datetime.timedelta(seconds=self.counter)))

    def display(self):
        # print(str(datetime.timedelta(seconds=self.counter)))
        self.displayLabel.setText(str(datetime.timedelta(seconds=self.counter)))

def main():
    app = QApplication(sys.argv)
    window = StopWatch()
    window.show()
    sys.exit(app.exec_())

main()

我正在寻找执行暂停功能。例如，当我单击“开始”，然后单击“暂停”，然后单击“开始”时，希望计数器正常运行。任何帮助表示赞赏。

Answer 1

尝试一下：

import sys
import datetime
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QPushButton, QGridLayout
from PyQt5.QtCore import QTimer, Qt
from PyQt5.QtGui import QFont, QPalette

class StopWatch(QWidget):
    def __init__(self):
        super().__init__()
        self.isRunning = False
        self.counter = 0

        self.setWindowTitle('Stop Watch')
        self.create_layout()

    def create_layout(self):
        self.timer = QTimer()
        self.timer.setInterval(1000)

        self.timer.timeout.connect(self.run)                                  # +++

        labelFormating = QPalette()
        labelFormating.setColor(QPalette.WindowText, Qt.darkBlue)

        self.startButton = QPushButton('Start')
        self.pauseButton = QPushButton('Pause')
        self.stopButton = QPushButton('Stop')

        self.startButton.setEnabled(True)
        self.pauseButton.setEnabled(False)
        self.stopButton.setEnabled(False)

        self.startButton.clicked.connect(self.start_timer)
        self.pauseButton.clicked.connect(self.pause)
        self.stopButton.clicked.connect(self.stop_timer)

        self.displayLabel = QLabel(str(datetime.timedelta(seconds=0)))
        self.displayLabel.setFont(QFont('Open Sans', 24))
        self.displayLabel.setPalette(labelFormating)

        gridLayout = QGridLayout()
        gridLayout.addWidget(self.displayLabel, 0, 0, 1, 3) 
        gridLayout.addWidget(self.startButton,  1, 0, 1, 1)
        gridLayout.addWidget(self.pauseButton,  1, 1, 1, 1)
        gridLayout.addWidget(self.stopButton,   1, 2, 1, 1)
        gridLayout.setAlignment(self.displayLabel, Qt.AlignCenter)
        self.setLayout(gridLayout)

    def start_timer(self, slot):
        self.startButton.setEnabled(False)
        self.pauseButton.setEnabled(True)
        self.stopButton.setEnabled(True)
        self.timer.start()

#        self.timer.timeout.connect(self.run)                            # ----

    def stop_timer(self):
        self.startButton.setEnabled(True)
        self.pauseButton.setEnabled(False)
        self.stopButton.setEnabled(False)
        self.isRunning = False
        self.timer.stop()

# ?        self.displayLabel.setText(str(datetime.timedelta(seconds=0)))
        self.counter = 0                                                  # +++

    def run(self):
        self.counter += 1
        self.display()

    def pause(self):
        self.startButton.setEnabled(True)
        self.pauseButton.setEnabled(False)
        self.stopButton.setEnabled(True)
        self.timer.stop()
#        self.displayLabel.setText(str(datetime.timedelta(seconds=self.counter)))

    def display(self):
        self.displayLabel.setText(str(datetime.timedelta(seconds=self.counter)))

def main():
    app = QApplication(sys.argv)
    window = StopWatch()
    window.show()
    sys.exit(app.exec_())

main()

QTimer在我暂停然后恢复时可以快一秒钟执行功能

1 个答案: