如何反转 QSlider 元素的 Ticklabels 以及如何使其可点击？

Question

我在 GUI 中插入了一个 QSlider 元素，并手动添加了一些刻度标签。然而我没有设法颠倒标签的顺序，即从 0-5 而不是 5-0。此外，我无法实现一种可以“单击”值的方式。这个问题是几天前另一个问题的扩展 (How to change the text in QPushbutton within a QButtongroup element after some user input?)

我在 QSlider 文档中查找了选项，并尝试更改 create_slider 函数中的 for 循环。我不知何故不明白为什么这不起作用，但也许它太微不足道了。至于使滑块可点击的尝试，我已经看到了一些解决方案，但我没有设法使它们在我的示例中起作用。

import os
from PyQt5 import QtCore, QtGui, QtWidgets

class App(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setGeometry(50, 50, 400, 500)
        self.initUI()

    def initUI(self):
        self.m_buttons = []
        self.s_labels = []

        group = QtWidgets.QButtonGroup(self)
        left_button = QtWidgets.QPushButton("Left", checkable=True)
        left_button.setFixedSize(100, 30)
        right_button = QtWidgets.QPushButton("Right", checkable=True)
        right_button.setFixedSize(100, 30)
        group.addButton(left_button)
        group.addButton(right_button)
        group.buttonClicked[QtWidgets.QAbstractButton].connect(self.update_text)

        label1 = QtWidgets.QLabel("Test1:")
        label2 = QtWidgets.QLabel("Test2:")

        self.m_widget = QtWidgets.QWidget()
        self.create_buttons()

        left_button.click()

        self.s_widget = QtWidgets.QWidget()
        self.create_slider()

        start_button = QtWidgets.QPushButton("Continue")
        start_button.setFixedSize(100, 50)

        check_button = QtWidgets.QPushButton("Check \nrecordings")
        check_button.setFixedSize(120, 50)

        ## start with the layout of the GUI ------------------------------
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)

        lay_tot = QtWidgets.QVBoxLayout(central_widget)

        h1lay = QtWidgets.QHBoxLayout()
        h1lay.addStretch(1)
        h1lay.addWidget(left_button)
        h1lay.addWidget(right_button)
        h1lay.addStretch(5)
        lay_tot.addLayout(h1lay)

        h2lay = QtWidgets.QHBoxLayout()
        h2lay.addStretch(1)
        h2lay.addWidget(label1)
        h2lay.addStretch(2)
        h2lay.addWidget(label2)
        h2lay.addStretch(1)
        lay_tot.addStretch(1)
        lay_tot.addLayout(h2lay)

        # insert the horizontal third layer (contacts + slider)
        h3lay = QtWidgets.QHBoxLayout()
        h3lay.addStretch(1)
        h3lay.addWidget(self.m_widget, alignment=QtCore.Qt.AlignCenter)
        h3lay.addStretch(2)
        h3lay.addWidget(self.s_widget, alignment=QtCore.Qt.AlignCenter)
        h3lay.addStretch(3)
        lay_tot.addLayout(h3lay)

        h4lay = QtWidgets.QHBoxLayout()
        h4lay.addStretch(5)
        h4lay.addWidget(check_button,2.4)
        h4lay.addWidget(start_button,2.4)
        h4lay.addStretch(1)

        lay_tot.addStretch(2)
        lay_tot.addLayout(h4lay)

    def create_buttons(self):
        coords = [
            (4, 1),
            (3, 0),
            (3, 1),
            (3, 2),
            (2, 0),
            (2, 1),
            (2, 2),
            (0, 1),
        ]
        group = QtWidgets.QButtonGroup(exclusive=True)
        grid = QtWidgets.QGridLayout(self.m_widget)
        for coord in coords:
            btn = QtWidgets.QPushButton(checkable=True)
            btn.setAutoExclusive(True)
            btn.setFixedSize(70, 50)
            grid.addWidget(btn, *coord)
            group.addButton(btn)
            self.m_buttons.append(btn)

        self.m_widget.setFixedSize(self.m_widget.sizeHint())

    @QtCore.pyqtSlot(QtWidgets.QAbstractButton)
    def update_text(self, btn):
        text = btn.text()
        texts = {
            "Left": ["1", "2", "3", "4", "5", "6", "7", "8"],
            "Right": ["9", "10", "11", "12", "13", "14", "15", "16"],
        }
        if text in texts:
            for btn, txt in zip(self.m_buttons, texts[text]):
                btn.setText(txt)
    def create_slider(self):
        # create the slider for the setting of amplitude
        hlay_slide = QtWidgets.QHBoxLayout(self.s_widget)
        slider = QtWidgets.QSlider(QtCore.Qt.Vertical)
        slider.setTickPosition(QtWidgets.QSlider.TicksLeft)
        slider.setTickInterval(1)
        slider.setSingleStep(.5)
        slider.setRange(0, 5)

        vlay_slide = QtWidgets.QVBoxLayout()
        for idx, val in enumerate(range(6, 0, -1)):
            lblSlider = QtWidgets.QLabel(str(idx))
            vlay_slide.addWidget(lblSlider)

        hlay_slide.addLayout(vlay_slide)
        hlay_slide.addWidget(slider)

if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = App()
    w.show()
    sys.exit(app.exec_())

Answer 1

试试看：

#import os
from PyQt5 import QtCore, QtGui, QtWidgets


class Slider(QtWidgets.QSlider):                                         # + <-----

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            val = self.pixelPosToRangeValue(event.pos())
            self.setValue(val)
        super(Slider, self).mousePressEvent(event)           

    def pixelPosToRangeValue(self, pos):
        opt = QtWidgets.QStyleOptionSlider()
        self.initStyleOption(opt)
        gr = self.style().subControlRect(QtWidgets.QStyle.CC_Slider, opt, QtWidgets.QStyle.SC_SliderGroove, self)
        sr = self.style().subControlRect(QtWidgets.QStyle.CC_Slider, opt, QtWidgets.QStyle.SC_SliderHandle, self)

        if self.orientation() == QtCore.Qt.Horizontal:
            sliderLength = sr.width()
            sliderMin = gr.x()
            sliderMax = gr.right() - sliderLength + 1
        else:
            sliderLength = sr.height()
            sliderMin = gr.y()
            sliderMax = gr.bottom() - sliderLength + 1;
        pr = pos - sr.center() + sr.topLeft()
        p = pr.x() if self.orientation() == QtCore.Qt.Horizontal else pr.y()
        return QtWidgets.QStyle.sliderValueFromPosition(self.minimum(), self.maximum(), p - sliderMin,
                                               sliderMax - sliderMin, opt.upsideDown)



class App(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setGeometry(50, 50, 400, 500)
        self.initUI()

    def initUI(self):
        self.m_buttons = []
        self.s_labels = []

        group = QtWidgets.QButtonGroup(self)
        left_button = QtWidgets.QPushButton("Left", checkable=True)
        left_button.setFixedSize(100, 30)
        right_button = QtWidgets.QPushButton("Right", checkable=True)
        right_button.setFixedSize(100, 30)
        group.addButton(left_button)
        group.addButton(right_button)
        group.buttonClicked[QtWidgets.QAbstractButton].connect(self.update_text)

        label1 = QtWidgets.QLabel("Test1:")
        label2 = QtWidgets.QLabel("Test2:")

        self.m_widget = QtWidgets.QWidget()
        self.create_buttons()

        left_button.click()

        self.s_widget = QtWidgets.QWidget()

        self.create_slider()

        start_button = QtWidgets.QPushButton("Continue")
        start_button.setFixedSize(100, 50)

        check_button = QtWidgets.QPushButton("Check \nrecordings")
        check_button.setFixedSize(120, 50)

        ## start with the layout of the GUI ------------------------------
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)

        lay_tot = QtWidgets.QVBoxLayout(central_widget)

        h1lay = QtWidgets.QHBoxLayout()
        h1lay.addStretch(1)
        h1lay.addWidget(left_button)
        h1lay.addWidget(right_button)
        h1lay.addStretch(5)
        lay_tot.addLayout(h1lay)

        h2lay = QtWidgets.QHBoxLayout()
        h2lay.addStretch(1)
        h2lay.addWidget(label1)
        h2lay.addStretch(2)
        h2lay.addWidget(label2)
        h2lay.addStretch(1)
        lay_tot.addStretch(1)
        lay_tot.addLayout(h2lay)

        # insert the horizontal third layer (contacts + slider)
        h3lay = QtWidgets.QHBoxLayout()
        h3lay.addStretch(1)
        h3lay.addWidget(self.m_widget, alignment=QtCore.Qt.AlignCenter)
        h3lay.addStretch(2)
        h3lay.addWidget(self.s_widget, alignment=QtCore.Qt.AlignCenter)
        h3lay.addStretch(3)
        lay_tot.addLayout(h3lay)

        h4lay = QtWidgets.QHBoxLayout()
        h4lay.addStretch(5)
        h4lay.addWidget(check_button,2.4)
        h4lay.addWidget(start_button,2.4)
        h4lay.addStretch(1)

        lay_tot.addStretch(2)
        lay_tot.addLayout(h4lay)

    def create_buttons(self):
        coords = [
            (4, 1),
            (3, 0),
            (3, 1),
            (3, 2),
            (2, 0),
            (2, 1),
            (2, 2),
            (0, 1),
        ]
        group = QtWidgets.QButtonGroup(exclusive=True)
        grid = QtWidgets.QGridLayout(self.m_widget)
        for coord in coords:
            btn = QtWidgets.QPushButton(checkable=True)
            btn.setAutoExclusive(True)
            btn.setFixedSize(70, 50)
            grid.addWidget(btn, *coord)
            group.addButton(btn)
            self.m_buttons.append(btn)

        self.m_widget.setFixedSize(self.m_widget.sizeHint())

    @QtCore.pyqtSlot(QtWidgets.QAbstractButton)
    def update_text(self, btn):
        text = btn.text()
        texts = {
            "Left": ["1", "2", "3", "4", "5", "6", "7", "8"],
            "Right": ["9", "10", "11", "12", "13", "14", "15", "16"],
        }
        if text in texts:
            for btn, txt in zip(self.m_buttons, texts[text]):
                btn.setText(txt)


    def create_slider(self):
        # create the slider for the setting of amplitude

# -       self.slider = QtWidgets.QSlider(QtCore.Qt.Vertical)
        self.slider = Slider(QtCore.Qt.Vertical)                         # +++
        self.slider.setTickPosition(QtWidgets.QSlider.TicksLeft)
        self.slider.setTickInterval(1)
#                     setSingleStep(int)        
# ?       self.slider.setSingleStep(0.5)
        self.slider.setRange(0, 5)
        self.slider.valueChanged.connect(self.valueChangedSlider)

        vlay_slide = QtWidgets.QVBoxLayout()
# -        for idx, val in enumerate(range(6, 0, -1)):
        for idx in range(5, -1, -1):                                     # +++
            lblSlider = QtWidgets.QLabel(str(idx))
            vlay_slide.addWidget(lblSlider)

        hlay_slide = QtWidgets.QHBoxLayout(self.s_widget)
        hlay_slide.addLayout(vlay_slide)
        hlay_slide.addWidget(self.slider)

#+++        
    def valueChangedSlider(self, value):
        print("value-> {}".format(value))    

if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = App()
    w.show()
    sys.exit(app.exec_())

---

更新

from PyQt5 import QtCore, QtGui, QtWidgets


class Slider(QtWidgets.QSlider):                                        

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            val = self.pixelPosToRangeValue(event.pos())
            self.setValue(val)
        super(Slider, self).mousePressEvent(event)           

    def pixelPosToRangeValue(self, pos):
        opt = QtWidgets.QStyleOptionSlider()
        self.initStyleOption(opt)
        gr = self.style().subControlRect(QtWidgets.QStyle.CC_Slider, opt, QtWidgets.QStyle.SC_SliderGroove, self)
        sr = self.style().subControlRect(QtWidgets.QStyle.CC_Slider, opt, QtWidgets.QStyle.SC_SliderHandle, self)

        if self.orientation() == QtCore.Qt.Horizontal:
            sliderLength = sr.width()
            sliderMin = gr.x()
            sliderMax = gr.right() - sliderLength + 1
        else:
            sliderLength = sr.height()
            sliderMin = gr.y()
            sliderMax = gr.bottom() - sliderLength + 1;
        pr = pos - sr.center() + sr.topLeft()
        p = pr.x() if self.orientation() == QtCore.Qt.Horizontal else pr.y()
        return QtWidgets.QStyle.sliderValueFromPosition(self.minimum(), self.maximum(), p - sliderMin,
                                               sliderMax - sliderMin, opt.upsideDown)



class App(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setGeometry(50, 50, 400, 500)
        self.initUI()

    def initUI(self):
        self.m_buttons = []
        self.s_labels = []

        group = QtWidgets.QButtonGroup(self)
        left_button = QtWidgets.QPushButton("Left", checkable=True)
        left_button.setFixedSize(100, 30)
        right_button = QtWidgets.QPushButton("Right", checkable=True)
        right_button.setFixedSize(100, 30)
        group.addButton(left_button)
        group.addButton(right_button)
        group.buttonClicked[QtWidgets.QAbstractButton].connect(self.update_text)

        label1 = QtWidgets.QLabel("Test1:")
        label2 = QtWidgets.QLabel("Test2:")

        self.m_widget = QtWidgets.QWidget()
        self.create_buttons()

        left_button.click()

        self.s_widget = QtWidgets.QWidget()

        self.create_slider()

        start_button = QtWidgets.QPushButton("Continue")
        start_button.setFixedSize(100, 50)

        check_button = QtWidgets.QPushButton("Check \nrecordings")
        check_button.setFixedSize(120, 50)

        ## start with the layout of the GUI ------------------------------
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)

        lay_tot = QtWidgets.QVBoxLayout(central_widget)

        h1lay = QtWidgets.QHBoxLayout()
        h1lay.addStretch(1)
        h1lay.addWidget(left_button)
        h1lay.addWidget(right_button)
        h1lay.addStretch(5)
        lay_tot.addLayout(h1lay)

        h2lay = QtWidgets.QHBoxLayout()
        h2lay.addStretch(1)
        h2lay.addWidget(label1)
        h2lay.addStretch(2)
        h2lay.addWidget(label2)
        h2lay.addStretch(1)
        lay_tot.addStretch(1)
        lay_tot.addLayout(h2lay)

        # insert the horizontal third layer (contacts + slider)
        h3lay = QtWidgets.QHBoxLayout()
        h3lay.addStretch(1)
        h3lay.addWidget(self.m_widget, alignment=QtCore.Qt.AlignCenter)
        h3lay.addStretch(2)
        h3lay.addWidget(self.s_widget, alignment=QtCore.Qt.AlignCenter)
        h3lay.addStretch(3)
        lay_tot.addLayout(h3lay)

        h4lay = QtWidgets.QHBoxLayout()
        h4lay.addStretch(5)
        h4lay.addWidget(check_button,2.4)
        h4lay.addWidget(start_button,2.4)
        h4lay.addStretch(1)

        lay_tot.addStretch(2)
        lay_tot.addLayout(h4lay)

    def create_buttons(self):
        coords = [
            (4, 1),
            (3, 0),
            (3, 1),
            (3, 2),
            (2, 0),
            (2, 1),
            (2, 2),
            (0, 1),
        ]
        group = QtWidgets.QButtonGroup(exclusive=True)
        grid = QtWidgets.QGridLayout(self.m_widget)
        for coord in coords:
            btn = QtWidgets.QPushButton(checkable=True)
            btn.setAutoExclusive(True)
            btn.setFixedSize(70, 50)
            grid.addWidget(btn, *coord)
            group.addButton(btn)
            self.m_buttons.append(btn)

        self.m_widget.setFixedSize(self.m_widget.sizeHint())

    @QtCore.pyqtSlot(QtWidgets.QAbstractButton)
    def update_text(self, btn):
        text = btn.text()
        texts = {
            "Left": ["1", "2", "3", "4", "5", "6", "7", "8"],
            "Right": ["9", "10", "11", "12", "13", "14", "15", "16"],
        }
        if text in texts:
            for btn, txt in zip(self.m_buttons, texts[text]):
                btn.setText(txt)

# +++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv      

                if self.isSignalConnected(btn, 'clicked()'):
                    btn.clicked.disconnect()
                btn.clicked.connect(self.btnClick)
                print(f"btn->{btn.text()}")

    def btnClick(self):
        sender = self.sender()
        print(f"sender->{sender.text()}")

    def isSignalConnected(self, obj, name):
        """ Определите, подключен ли сигнал
        :param obj:        объекты
        :param name:       Имя сигнала, например, clicked()
        """
        index = obj.metaObject().indexOfMethod(name)
        if index > -1:
            method = obj.metaObject().method(index)
            if method:
                return obj.isSignalConnected(method)
        return False

# +++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^



    def create_slider(self):
        # create the slider for the setting of amplitude
        self.slider = Slider(QtCore.Qt.Vertical)                         
        self.slider.setTickPosition(QtWidgets.QSlider.TicksLeft)
        self.slider.setTickInterval(1)
        self.slider.setRange(0, 5)
        self.slider.valueChanged.connect(self.valueChangedSlider)

        vlay_slide = QtWidgets.QVBoxLayout()
        for idx in range(5, -1, -1):                                    
            lblSlider = QtWidgets.QLabel(str(idx))
            vlay_slide.addWidget(lblSlider)

        hlay_slide = QtWidgets.QHBoxLayout(self.s_widget)
        hlay_slide.addLayout(vlay_slide)
        hlay_slide.addWidget(self.slider)

    def valueChangedSlider(self, value):
        print("value-> {}".format(value))    


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = App()
    w.show()
    sys.exit(app.exec_())