移动 QSlider 到鼠标点击位置

Question

我有一个QSlider，我想在用户按下鼠标左键时移动到鼠标光标的位置。我一直在四处寻找，找不到任何最近解决我问题的东西。

这是我的滑块。我希望能够点击让滑块跳转到鼠标点击的位置。我可以拖动滑块，但我希望能够单击。我测试了点击 Dolphin 文件管理器中的滑块。它递增而不是跳到鼠标的确切位置。

QSlider has very few of its own functions [...]

这表明没有内置方法可以执行此操作。有没有办法得到鼠标点击的位置并将滑块移动到那个点？

Answer 1

QSlider 没有这样的功能，因此实现此功能的唯一方法是编写自定义小部件并覆盖其中的鼠标单击：

class Slider(QSlider):

    def mousePressEvent(self, e):
        if e.button() == Qt.LeftButton:
            e.accept()
            x = e.pos().x()
            value = (self.maximum() - self.minimum()) * x / self.width() + self.minimum()
            self.setValue(value)
        else:
            return super().mousePressEvent(self, e)

请注意，此代码仅适用于水平滑块。

Answer 2

解决方法是计算位置并设置在mousePressEvent中，计算不像算术计算那么容易，因为它取决于每个OS的样式和样式表所以我们必须使用 QStyle，如下所示：

from PyQt5 import QtCore, QtWidgets


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

    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)


if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = QtWidgets.QWidget()
    flay = QtWidgets.QFormLayout(w)
    w1 = QtWidgets.QSlider(QtCore.Qt.Horizontal)
    w2 = Slider(QtCore.Qt.Horizontal)
    flay.addRow("default: ", w1)
    flay.addRow("modified: ", w2)
    w.show()
    sys.exit(app.exec_())

Answer 3

我相信我有一个不太复杂的解决方案：

from PyQt5.QtWidgets import QSlider


class ClickSlider(QSlider):
    """A slider with a signal that emits its position when it is pressed. Created to get around the slider only updating when the handle is dragged, but not when a new position is clicked"""

    sliderPressedWithValue = QSignal(int)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.sliderPressed.connect(self.on_slider_pressed)

    def on_slider_pressed(self):
        """emits a more descriptive signal when pressed (with slider value during the press event)"""
        self.sliderPressedWithValue.emit(self.value())

然后确保像这样连接到您正在更新的任何内容：

# example if you're updating a QMediaPlayer object
from PyQt5.QtMultimedia import QMediaPlayer
player = QMediaPlayer()

slider = ClickSlider()
slider.sliderPressedWithValue.connect(player.setPosition)  # updates on click
slider.sliderMoved.connect(player.setPosition)  # updates on drag

Answer 4

试试这个代码。

class MySliderStyle : public QProxyStyle
{
public:
    virtual int styleHint(StyleHint hint, const QStyleOption * option = 0, const QWidget * widget = 0, QStyleHintReturn * returnData = 0) const{
        if (hint == QStyle::SH_Slider_AbsoluteSetButtons)
        {
            return Qt::LeftButton;
        }
        else
        {
            return QProxyStyle::styleHint(hint, option, widget, returnData);
        }
  }
};


ui->mySlider->setStyle(new MySliderStyle);

移动 QSlider 到鼠标点击位置

Moving QSlider to Mouse Click Position

python

python-3.x

pyqt

pyqt5

qslider