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python - 如何在单击鼠标的位置绘制和填充 PyQtGraph 图中的矩形

问题描述

我正在使用 PyQt5 和 PyQtGraph。我已经简化了下面的示例代码。然后我想在每次点击鼠标的位置在绘图视图中绘制一个红色的小矩形，从而在绘图视图中累积几个红色矩形。下面的代码有一个#??? 评论我需要一些帮助来绘制红色矩形的代码。

import sys
from PyQt5 import QtWidgets
import numpy as np
import pyqtgraph as pg
from pyqtgraph import PlotWidget, plot

# *********************************************************************************************
# *********************************************************************************************

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.setWindowTitle("My MainWindow")
        self.qPlotWidget = pg.PlotWidget(self)
        self.qPlotWidget.setLabel("bottom", "X-Axis")
        self.qPlotWidget.setLabel("left", "Y-Axis")
        self.qPlotWidget.scene().sigMouseClicked.connect(self.mouseClickedEvent)

        data1 = np.zeros((2, 2), float) # create the array to hold the data
        data1[0] = np.array((1.0, 10.0))
        data1[1] = np.array((2.0, 20.0))

        pen1 = pg.mkPen(color=(255,0,0), width=1) # red
        self.qPlotWidget.plot(data1, pen=pen1, name="data1")

    def mouseClickedEvent(self, event):
        print("mouseClickedEvent")
        pos = event.scenePos()
        if (self.qPlotWidget.sceneBoundingRect().contains(pos)):
            mousePoint = self.qPlotWidget.plotItem.vb.mapSceneToView(pos)
            print("mousePoint=", mousePoint)

            # draw and fill a 2-pixel by 2-pixel red rectangle where
            # the mouse was clicked at [mousePoint.x(), mousePoint.y()]
            # ??? add code here

    def resizeEvent(self, event):
        size = self.geometry()
        self.qPlotWidget.setGeometry(10, 10, size.width()-20, size.height()-20)

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)

    w = MainWindow()
    screen = QtWidgets.QDesktopWidget().screenGeometry()
    w.setGeometry(100, 100, screen.width()-200, screen.height()-200) # x, y, Width, Height
    w.show()

    sys.exit(app.exec_())

标签： pythonpyqt5rectanglespyqtgraph

解决方案

您可以做的是创建一个空的散点图项目并将其添加到self.qPlotWidget. 然后mousrClickedEvent你可以将鼠标位置添加到这个散点图项目的点列表中，即

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        .... as before ....

        # add empty scatter plot item with a red brush and a square as the symbol to plot widget
        brush = pg.mkBrush(color=(255,0,0))
        self.scatterItem = pg.ScatterPlotItem(pen=None, size=10, brush=brush, symbol='s')
        self.qPlotWidget.addItem(self.scatterItem)


    def mouseClickedEvent(self, event):
        pos = event.scenePos()
        if (self.qPlotWidget.sceneBoundingRect().contains(pos)):
            mousePoint = self.qPlotWidget.plotItem.vb.mapSceneToView(pos)

            # add point to scatter item
            self.scatterItem.addPoints([mousePoint.x()], [mousePoint.y()])

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