PyQt 中的切换按钮

Question

我已经在 PyQt4 中实现了以下切换按钮，但我不明白为什么它在“关闭”状态时没有按预期运行。我无法理解似乎是什么问题。任何帮助都将是宝贵的并受到高度赞赏。

在这里，您可以找到我的代码。

from PyQt4.QtCore import QObject
from PyQt4.QtGui import QPen
from PyQt4.QtGui import QBrush
from PyQt4.QtGui import QPalette
from PyQt4.QtGui import QAbstractButton
from PyQt4.QtGui import QPainter
from PyQt4.QtGui import QApplication
from PyQt4.QtCore import QRectF
from PyQt4.QtGui import QLinearGradient, QGradient
from PyQt4.QtCore import QPropertyAnimation
from PyQt4.QtCore import QEasingCurve
from PyQt4.QtCore import Qt, QSize
from PyQt4.QtCore import pyqtProperty, pyqtSlot


class QSlideSwitchPrivate(QObject):

    def __init__(self, q):
        QObject.__init__(self)

        self._position = 0
        self._sliderShape = QRectF()
        self._gradient = QLinearGradient()
        self._gradient.setSpread(QGradient.PadSpread)
        self._qPointer = q

        self.animation = QPropertyAnimation(self)
        self.animation.setTargetObject(self)
        self.animation.setPropertyName("position")
        self.animation.setStartValue(0)
        self.animation.setEndValue(1)
        self.animation.setDuration(300)
        self.animation.setEasingCurve(QEasingCurve.InOutExpo)

    def __del__(self):
        del self.animation

    @pyqtProperty(float)
    def position(self):
        return self._position

    @position.setter
    def position(self, value):
        self._position = value
        self._qPointer.repaint()

    def drawSlider(self, painter):
        margin = 3
        r = self._qPointer.rect().adjusted(0,0,-1,-1)
        dx = (r.width() - self._sliderShape.width()) * self._position
        sliderRect = self._sliderShape.translated(dx, 0)
        painter.setPen(Qt.NoPen)

        # basic settings
        shadow = self._qPointer.palette().color(QPalette.Dark)
        light = self._qPointer.palette().color(QPalette.Light)
        button = self._qPointer.palette().color(QPalette.Button)

        # draw background
        # draw outer background
        self._gradient.setColorAt(0, shadow.darker(130))
        self._gradient.setColorAt(1, light.darker(130))
        self._gradient.setStart(0, r.height())
        self._gradient.setFinalStop(0, 0)
        painter.setBrush(self._gradient)
        painter.drawRoundedRect(r, 15, 15)

        # draw background
        # draw inner background
        self._gradient.setColorAt(0, shadow.darker(140))
        self._gradient.setColorAt(1, light.darker(160))
        self._gradient.setStart(0, 0)
        self._gradient.setFinalStop(0, r.height())
        painter.setBrush(self._gradient)
        painter.drawRoundedRect(r.adjusted(margin, margin, -margin, -margin), 15, 15)

        # draw slider
        self._gradient.setColorAt(0, button.darker(130))
        self._gradient.setColorAt(1, button)

        # draw outer slider
        self._gradient.setStart(0, r.height())
        self._gradient.setFinalStop(0, 0)
        painter.setBrush(self._gradient)
        painter.drawRoundedRect(sliderRect.adjusted(margin, margin, -margin, -margin), 10, 15)

        # draw inner slider
        self._gradient.setStart(0, 0)
        self._gradient.setFinalStop(0, r.height())
        painter.setBrush(self._gradient)
        painter.drawRoundedRect(sliderRect.adjusted(2.5 * margin, 2.5 * margin, -2.5 * margin, - 2.5 * margin), 5, 15)

        # draw text
        if self.animation.state() == QPropertyAnimation.Running:
            return #don't draw any text while animation is running

        font = self._qPointer.font()
        self._gradient.setColorAt(0, light)
        self._gradient.setColorAt(1, shadow)
        self._gradient.setStart(0, r.height() / 2.0 + font.pointSizeF())
        self._gradient.setFinalStop(0, r.height() / 2.0 - font.pointSizeF())
        painter.setFont(font)
        painter.setPen(QPen(QBrush(self._gradient), 0))

        if self._qPointer.isChecked():
            painter.drawText(0, 0, r.width() / 2, r.height()-1, Qt.AlignCenter, "ON")
        else:
            painter.drawText( r.width() / 2, 0, r.width() / 2, r.height() - 1, Qt.AlignCenter, "OFF")

    def updateSliderRect(self, size):
        self._sliderShape.setWidth(size.width() / 2.0)
        self._sliderShape.setHeight(size.height() - 1.0)

    @pyqtSlot(bool, name='animate')
    def animate(self, checked):
        self.animation.setDirection = QPropertyAnimation.Forward if checked else QPropertyAnimation.Backward
        print(self.animation.setDirection)
        self.animation.start()


class QSlideSwitch(QAbstractButton):
    def __init__(self, parent = None):
        super(QAbstractButton, self).__init__(parent)

        self.d_ptr = QSlideSwitchPrivate( self )
        self.clicked.connect( self.d_ptr.animate )
        self.d_ptr.animation.finished.connect( self.update )

    def __del__(self):
        del self.d_ptr

    def sizeHint(self):
        return QSize(48, 28)

    def hitButton(self, point):
        return self.rect().contains(point)

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        self.d_ptr.drawSlider(painter)

    def resizeEvent(self, event):
        self.d_ptr.updateSliderRect(event.size())
        self.repaint()


if __name__ == '__main__':

    import sys

    app = QApplication(sys.argv)

    switcher = QSlideSwitch()
    switcher.setCheckable(True)
    switcher.show()

    sys.exit(app.exec_())

Answer 1

问题是你没有更改QPropertyAnimation的地址。你不能使用{your QPropertyAnimation}.setDirection = {some value}，而是{your QPropertyAnimation}.setDirection({some value})。您必须更改为

@pyqtSlot(bool, name='animate')
def animate(self, checked):
    self.animation.setDirection(QPropertyAnimation.Forward if checked else QPropertyAnimation.Backward)
    self.animation.start()