如何在不重新创建的情况下更改 BarGraphItem 的颜色？

Question

我正在使用 pyqtgraph 中的 BarGraphItem 创建条形图，如果单击/选择了条形图，我想更改条形图的外观，但我不知道如何执行此操作。

条形图显示良好，我可以设置原始颜色，但在任何地方都找不到任何关于如何更改颜色的参考（在我的情况下是为了反映所选状态）

Answer 1

重载PlotWidget 和BarGraphItem。检查您的PlotWidget.mousePressEvent 的QMouseEvent 位置是否在您的条形之一内：

import pyqtgraph as pg

class MyBarGraphItem(pg.BarGraphItem):

    def __init__(self):
        super().__init__()

    def setAttr(self, **opts):
        if 'x' in opts:
            self.x = opts['x']
        if 'height' in opts:
            self.height = opts['height']
        if 'width' in opts:
            self.width = opts['width']
        if 'brushes' in opts:
            self.brushes = opts['brushes']
        super().setOpts(**opts)

class MyPlot(pg.PlotWidget):

    def __init__(self):
        super().__init__()
        self.bars = None

    def mousePressEvent(self, ev):
        pos = self.getPlotItem().vb.mapSceneToView(ev.pos())
        if self.bars is not None:
            for i,_ in enumerate(self.bars.x):
                if self.bars.x[i]-self.bars.width/2 < pos.x() < self.bars.x[i]+self.bars.width/2\
                        and 0 < pos.y() < self.bars.height[i]:
                    b = self.bars.brushes
                    b[i] = pg.QtGui.QColor(255,255,255)
                    self.bars.setAttr(brushes=b)
                    print('clicked on bar '+str(i))
                    ev.accept()
        super().mousePressEvent(ev)

    def addBars(self, bars):
        self.bars = bars
        self.addItem(bars)

if __name__ == '__main__':

    app = pg.mkQApp()

    plot = MyPlot()

    bars = MyBarGraphItem()
    bars.setAttr(brushes=[pg.hsvColor(float(x) / 5) for x in range(5)], x=[i for i in range(5)], height=[1,5,2,4,3], width=0.5)

    plot.addBars(bars)

    plot.show()

    app.exec()