我正在尝试为项目创建一个PyQt计时器应用程序。我使用QtDesigner设计了布局，我几乎完成了所有代码。只有一个小问题。我想为我的计时器制作一个停止按钮，但每次我做它时，只要我再次按下启动计时器就会重置。只要计时器还没有超时，我希望它继续。我做了一次部分修复，这意味着计时器确实继续，但问题是数字进入负数而不是仅停在零。我是Python的新手，对PyQt来说更是如此，所以如果解决方案看起来很明显，我很抱歉（我花了好几天试图解决它）。
无论如何这里是代码（它自己重置的代码）：
from PyQt4 import QtCore, QtGui
import time
from PyQt4.QtCore import pyqtSlot,SIGNAL,SLOT
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_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName(_fromUtf8("MainWindow"))
MainWindow.resize(351, 200)
MainWindow.setMinimumSize(QtCore.QSize(0, 200))
icon = QtGui.QIcon()
icon.addPixmap(QtGui.QPixmap(_fromUtf8("../../../Pictures/clock-icon-md.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
MainWindow.setWindowIcon(icon)
self.centralwidget = QtGui.QWidget(MainWindow)
self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
self.gridLayout = QtGui.QGridLayout(self.centralwidget)
self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
self.display = QtGui.QLCDNumber(self.centralwidget)
font = QtGui.QFont()
font.setKerning(True)
self.display.setFont(font)
self.display.setLayoutDirection(QtCore.Qt.LeftToRight)
self.display.setAutoFillBackground(False)
self.display.setFrameShape(QtGui.QFrame.Box)
self.display.setFrameShadow(QtGui.QFrame.Raised)
self.display.setMidLineWidth(-2)
self.display.setSmallDecimalPoint(False)
self.display.setNumDigits(5)
self.display.setDigitCount(5)
self.display.setMode(QtGui.QLCDNumber.Dec)
self.display.setSegmentStyle(QtGui.QLCDNumber.Filled)
self.display.setProperty("value", 0.0)
self.display.setProperty("intValue", 0)
self.display.setObjectName(_fromUtf8("display"))
self.gridLayout.addWidget(self.display, 0, 0, 1, 5)
self.minBox = QtGui.QSpinBox(self.centralwidget)
self.minBox.setAlignment(QtCore.Qt.AlignLeading|QtCore.Qt.AlignLeft|QtCore.Qt.AlignVCenter)
self.minBox.setMaximum(60)
self.minBox.setObjectName(_fromUtf8("minBox"))
self.gridLayout.addWidget(self.minBox, 2, 0, 1, 1)
self.secBox = QtGui.QSpinBox(self.centralwidget)
self.secBox.setMaximum(60)
self.secBox.setObjectName(_fromUtf8("secBox"))
self.gridLayout.addWidget(self.secBox, 2, 1, 1, 1)
self.secLabel = QtGui.QLabel(self.centralwidget)
sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.secLabel.sizePolicy().hasHeightForWidth())
self.secLabel.setSizePolicy(sizePolicy)
self.secLabel.setObjectName(_fromUtf8("secLabel"))
self.gridLayout.addWidget(self.secLabel, 3, 1, 1, 1)
self.minLabel = QtGui.QLabel(self.centralwidget)
sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.minLabel.sizePolicy().hasHeightForWidth())
self.minLabel.setSizePolicy(sizePolicy)
self.minLabel.setObjectName(_fromUtf8("minLabel"))
self.gridLayout.addWidget(self.minLabel, 3, 0, 1, 1)
self.startBtn = QtGui.QPushButton(self.centralwidget)
self.startBtn.setObjectName(_fromUtf8("startBtn"))
self.gridLayout.addWidget(self.startBtn, 2, 2, 1, 1)
self.ResetBtn = QtGui.QPushButton(self.centralwidget)
self.ResetBtn.setWhatsThis(_fromUtf8(""))
self.ResetBtn.setObjectName(_fromUtf8("ResetBtn"))
self.gridLayout.addWidget(self.ResetBtn, 2, 4, 1, 1)
self.stopBtn = QtGui.QPushButton(self.centralwidget)
self.stopBtn.setObjectName(_fromUtf8("stopBtn"))
self.gridLayout.addWidget(self.stopBtn, 2, 3, 1, 1)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtGui.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 351, 21))
self.menubar.setObjectName(_fromUtf8("menubar"))
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtGui.QStatusBar(MainWindow)
self.statusbar.setObjectName(_fromUtf8("statusbar"))
MainWindow.setStatusBar(self.statusbar)
self.msgBox = QtGui.QMessageBox()
self.msgBox.setWindowTitle('Finished')
self.msgBox.setIcon (QtGui.QMessageBox.Information)
self.msgBox.setText("Time Out !!")
stopButton = self.msgBox.addButton("Stop", QtGui.QMessageBox.ActionRole)
ignoreButton = self.msgBox.addButton(QtGui.QMessageBox.Ignore)
self.started = False
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
self.home()
def retranslateUi(self, MainWindow):
MainWindow.setWindowTitle(_translate("MainWindow", "Timer Application", None))
self.secLabel.setText(_translate("MainWindow", "Seconds", None))
self.minLabel.setText(_translate("MainWindow", "Minutes", None))
self.startBtn.setToolTip(_translate("MainWindow", "<html><head/><body><p>Start the timer</p></body></html>", None))
self.startBtn.setStatusTip(_translate("MainWindow", "Start the timer", None))
self.startBtn.setText(_translate("MainWindow", "Start", None))
self.ResetBtn.setToolTip(_translate("MainWindow", "<html><head/><body><p>Reset the timer</p></body></html>", None))
self.ResetBtn.setStatusTip(_translate("MainWindow", "Reset the timer", None))
self.ResetBtn.setText(_translate("MainWindow", "Reset", None))
self.stopBtn.setToolTip(_translate("MainWindow", "<html><head/><body><p>Stop the timer</p></body></html>", None))
self.stopBtn.setStatusTip(_translate("MainWindow", "Stop the timer", None))
self.stopBtn.setText(_translate("MainWindow", "Stop", None))
def home(self):
self.startBtn.clicked.connect(self.value_calc)
self.stopBtn.clicked.connect(self.stop_timer)
self.ResetBtn.clicked.connect(self.reset_timer)
def stop_timer(self):
self.timer.stop()
if self.value != -1:
self.started = True
else:
self.started = False
def displayer(self):
self.display.display(self.value)
self.value -= 1
if self.value == -1:
self.display.display(0)
self.timer.stop()
self.msgBox.show()
def value_calc(self):
sec_value = self.secBox.value()
min_value = self.minBox.value()
min_value *= 60
self.value = sec_value + min_value
if self.value != -1:
if self.started == False:
self.timer = QtCore.QTimer()
self.timer.timeout.connect(self.displayer)
self.timer.start(1000)
else:
self.timer.start(1000)
else:
pass
def reset_timer(self):
self.timer.stop()
self.display.display(0)
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
MainWindow = QtGui.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
答案 0 :(得分：0)
程序中有很多不必要的if语句和一个名为self.started的不必要变量。您还需要一种方法告诉value_calc函数检查self.value的当前值，这只能通过在self.value函数中设置home的默认值来实现（你实际上应该使用__init__）当你按下重置按钮时你还需要将self.value重置回它的初始值，这样你就不会从它停止的地方开始计数，这也是阻止您的计时器计入负值，因为value_calc始终会检查self.value是否小于零
以下是最终代码：
from PyQt4 import QtCore, QtGui
import time
from PyQt4.QtCore import pyqtSlot,SIGNAL,SLOT
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_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName(_fromUtf8("MainWindow"))
MainWindow.resize(351, 200)
MainWindow.setMinimumSize(QtCore.QSize(0, 200))
icon = QtGui.QIcon()
icon.addPixmap(QtGui.QPixmap(_fromUtf8("../../../Pictures/clock-icon-md.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
MainWindow.setWindowIcon(icon)
self.centralwidget = QtGui.QWidget(MainWindow)
self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
self.gridLayout = QtGui.QGridLayout(self.centralwidget)
self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
self.display = QtGui.QLCDNumber(self.centralwidget)
font = QtGui.QFont()
font.setKerning(True)
self.display.setFont(font)
self.display.setLayoutDirection(QtCore.Qt.LeftToRight)
self.display.setAutoFillBackground(False)
self.display.setFrameShape(QtGui.QFrame.Box)
self.display.setFrameShadow(QtGui.QFrame.Raised)
self.display.setMidLineWidth(-2)
self.display.setSmallDecimalPoint(False)
self.display.setNumDigits(5)
self.display.setDigitCount(5)
self.display.setMode(QtGui.QLCDNumber.Dec)
self.display.setSegmentStyle(QtGui.QLCDNumber.Filled)
self.display.setProperty("value", 0.0)
self.display.setProperty("intValue", 0)
self.display.setObjectName(_fromUtf8("display"))
self.gridLayout.addWidget(self.display, 0, 0, 1, 5)
self.minBox = QtGui.QSpinBox(self.centralwidget)
self.minBox.setAlignment(QtCore.Qt.AlignLeading|QtCore.Qt.AlignLeft|QtCore.Qt.AlignVCenter)
self.minBox.setMaximum(60)
self.minBox.setObjectName(_fromUtf8("minBox"))
self.gridLayout.addWidget(self.minBox, 2, 0, 1, 1)
self.secBox = QtGui.QSpinBox(self.centralwidget)
self.secBox.setMaximum(60)
self.secBox.setObjectName(_fromUtf8("secBox"))
self.gridLayout.addWidget(self.secBox, 2, 1, 1, 1)
self.secLabel = QtGui.QLabel(self.centralwidget)
sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.secLabel.sizePolicy().hasHeightForWidth())
self.secLabel.setSizePolicy(sizePolicy)
self.secLabel.setObjectName(_fromUtf8("secLabel"))
self.gridLayout.addWidget(self.secLabel, 3, 1, 1, 1)
self.minLabel = QtGui.QLabel(self.centralwidget)
sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.minLabel.sizePolicy().hasHeightForWidth())
self.minLabel.setSizePolicy(sizePolicy)
self.minLabel.setObjectName(_fromUtf8("minLabel"))
self.gridLayout.addWidget(self.minLabel, 3, 0, 1, 1)
self.startBtn = QtGui.QPushButton(self.centralwidget)
self.startBtn.setObjectName(_fromUtf8("startBtn"))
self.gridLayout.addWidget(self.startBtn, 2, 2, 1, 1)
self.ResetBtn = QtGui.QPushButton(self.centralwidget)
self.ResetBtn.setWhatsThis(_fromUtf8(""))
self.ResetBtn.setObjectName(_fromUtf8("ResetBtn"))
self.gridLayout.addWidget(self.ResetBtn, 2, 4, 1, 1)
self.stopBtn = QtGui.QPushButton(self.centralwidget)
self.stopBtn.setObjectName(_fromUtf8("stopBtn"))
self.gridLayout.addWidget(self.stopBtn, 2, 3, 1, 1)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtGui.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 351, 21))
self.menubar.setObjectName(_fromUtf8("menubar"))
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtGui.QStatusBar(MainWindow)
self.statusbar.setObjectName(_fromUtf8("statusbar"))
MainWindow.setStatusBar(self.statusbar)
self.msgBox = QtGui.QMessageBox()
self.msgBox.setWindowTitle('Finished')
self.msgBox.setIcon (QtGui.QMessageBox.Information)
self.msgBox.setText("Time Out !!")
stopButton = self.msgBox.addButton("Stop", QtGui.QMessageBox.ActionRole)
ignoreButton = self.msgBox.addButton(QtGui.QMessageBox.Ignore)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
self.home()
def retranslateUi(self, MainWindow):
MainWindow.setWindowTitle(_translate("MainWindow", "Timer Application", None))
self.secLabel.setText(_translate("MainWindow", "Seconds", None))
self.minLabel.setText(_translate("MainWindow", "Minutes", None))
self.startBtn.setToolTip(_translate("MainWindow", "<html><head/><body><p>Start the timer</p></body></html>", None))
self.startBtn.setStatusTip(_translate("MainWindow", "Start the timer", None))
self.startBtn.setText(_translate("MainWindow", "Start", None))
self.ResetBtn.setToolTip(_translate("MainWindow", "<html><head/><body><p>Reset the timer</p></body></html>", None))
self.ResetBtn.setStatusTip(_translate("MainWindow", "Reset the timer", None))
self.ResetBtn.setText(_translate("MainWindow", "Reset", None))
self.stopBtn.setToolTip(_translate("MainWindow", "<html><head/><body><p>Stop the timer</p></body></html>", None))
self.stopBtn.setStatusTip(_translate("MainWindow", "Stop the timer", None))
self.stopBtn.setText(_translate("MainWindow", "Stop", None))
def home(self):
self.startBtn.clicked.connect(self.value_calc)
self.stopBtn.clicked.connect(self.stop_timer)
self.ResetBtn.clicked.connect(self.reset_timer)
self.value = -1
def stop_timer(self):
self.timer.stop()
def displayer(self):
self.display.display(self.value)
self.value -= 1
if self.value == -1:
self.display.display(0)
self.timer.stop()
self.msgBox.show()
def value_calc(self):
if self.value < 0:
sec_value = self.secBox.value()
min_value = self.minBox.value()
min_value *= 60
self.value = sec_value + min_value
self.timer = QtCore.QTimer()
self.timer.timeout.connect(self.displayer)
self.timer.start(1000)
else:
self.timer.start(1000)
def reset_timer(self):
self.timer.stop()
self.display.display(0)
self.value = -1
也适用于下次比较python中的布尔值
if x == True或if x == False
相当于
if x或if not x