我在写小工具的时候，需要一个支持小数的滑动条。

我QSpinBox都找到了QDoubleSpinBox，QSlider愣是没找到对应的东西。

网上有好多对QSlider封装实现QDoubleSlider的文章。

似乎Qt真的没有这个东西，需要我们自行实现。

于是我也封装了一个，用起来没啥问题，遂贴出来，供大家参考。

只要依赖没问题，代码可以直接执行，执行之后的效果大致如下：

代码如下：

import numpy
import sys
import PySide6
import PySide6.QtCore
import PySide6.QtWidgets
from PySide6 import QtWidgets
from typing import Optional


class QDoubleSlider(PySide6.QtWidgets.QSlider):
    """"""
    # 基于QSlider实现DoubleSlider
    # https://blog.csdn.net/weixin_43435307/article/details/111830223

    valueChanged = PySide6.QtCore.Signal(float)

    def __init_subclass__(cls):
        """"""
        return super().__init_subclass__()

    def __init__(
        self,
        orientation: PySide6.QtCore.Qt.Orientation,
        parent: Optional[PySide6.QtWidgets.QWidget] = None,
    ) -> None:
        """"""
        super().__init__(orientation=orientation, parent=parent)

        # 以下写法属于无意间找到的, 现记录于此, 我个人不喜欢这种写法, 该写法参考了如下链接:
        # https://doc.qt.io/qtforpython-6/tutorials/basictutorial/signals_and_slots.html#specifying-signals-and-slots-by-method-signature-strings
        # PySide6.QtCore.QObject.connect(self, PySide6.QtCore.SIGNAL("valueChanged(int)"), self, PySide6.QtCore.SLOT("valueIntToDouble(int)"))
        super().valueChanged.connect(self.valueIntToDouble)

        self.__min_value: float = super().minimum()
        self.__max_value: float = super().maximum()
        self.__once_step: int = super().singleStep()
        self.__sync_data()

    def setMaximum(self, arg__1: float) -> None:
        """"""
        self.__max_value = arg__1
        self.__sync_data()

    def setMinimum(self, arg__1: float) -> None:
        """"""
        self.__min_value = arg__1
        self.__sync_data()

    def setRange(self, _min: float, _max: float) -> None:
        """"""
        self.__min_value = _min
        self.__max_value = _max
        self.__sync_data()

    def setSingleStep(self, val: float) -> None:
        """"""
        self.__once_step = val
        self.__sync_data()

    def setValue(self, arg__1: float) -> None:
        """"""
        PySide6.QtWidgets.QSlider.setValue(
            self,
            round(pow(10, self.__precision) * arg__1, ndigits=9)
        )

    @PySide6.QtCore.Slot(int)
    def valueIntToDouble(self, value: int):
        """"""
        val: float = round(pow(10, self.__precision * -1) * value, ndigits=9)
        self.valueChanged.emit(val)

    @classmethod
    def __float_ndigit(cls, val) -> int:
        """"""
        return len(numpy.format_float_positional(val, precision=9).split(sep='.')[1])

    def __sync_data(self) -> None:
        """"""
        self.__precision: int = max(
            self.__float_ndigit(self.__min_value),
            self.__float_ndigit(self.__max_value),
            self.__float_ndigit(self.__once_step),
        )
        PySide6.QtWidgets.QSlider.setRange(
            self,
            round(pow(10, self.__precision) * self.__min_value, ndigits=9),
            round(pow(10, self.__precision) * self.__max_value, ndigits=9)
        )
        PySide6.QtWidgets.QSlider.setSingleStep(
            self,
            round(pow(10, self.__precision) * self.__once_step, ndigits=9)
        )

    @classmethod
    def _test(cls) -> None:
        """"""
        qapp = QtWidgets.QApplication.instance()
        if qapp is None:
            qapp: QtWidgets.QApplication = QtWidgets.QApplication(sys.argv)

        is_custom: bool = True

        slider = QDoubleSlider(PySide6.QtCore.Qt.Horizontal) if is_custom else PySide6.QtWidgets.QSlider(PySide6.QtCore.Qt.Horizontal)
        print("current: slider,type      :", type(slider))
        print("default: slider.minimum   :", slider.minimum())
        print("default: slider.maximum   :", slider.maximum())
        print("default: slider.singleStep:", slider.singleStep())
        slider.setRange(0.5, 1.5)
        slider.setSingleStep(0.1)
        slider.valueChanged.connect(lambda _: print(_))
        slider.show()

        qapp.exec()


if __name__ == "__main__":
    QDoubleSlider._test()

。