pytqt图形线的鼠标坐标

Question

每当我将鼠标移到图表顶部时，我都会尝试获取随机函数图的 (x,y) 值。我正在使用 pyqtgraph.SignalProxy 并将其连接到回调 mousedMoved。

我得到这个错误： NameError：未定义全局名称“mouseMoved”

代码如下：

import sys
from pyqtgraph.Qt import QtGui, QtCore
import numpy as np
import pyqtgraph as pg
import time
import random

class TestClass(QtGui.QMainWindow):
  #####################################################
  def __init__(self):
    super(TestClass, self).__init__()
    self.initUI()

  #####################################################
  # GUI construction
  def initUI(self):
    win = pg.GraphicsWindow(title="Mouse Point, x & y")

    # creates plot
    self.plot = pg.PlotWidget()
    self.plot.setLabel('left', "B", units='T')
    self.plot.setLabel('bottom', "t", units='s')
    self.plot.showGrid(x=1, y=1, alpha=None)
    self.setCentralWidget(win)
    self.setGeometry(600, 600, 600, 600)
    self.setWindowTitle('Mouse Point, x& y GUI')

    # Create some widgets to be placed inside
    btnRandon = QtGui.QPushButton('Random Function')


    # Create a grid layout to manage the widgets size and position
    layout = QtGui.QGridLayout()
    win.setLayout(layout)

    # Add widgets to the layout in their proper positions
    layout.addWidget(btnRandon, 0, 0) # button to show or hide the OldB
    layout.addWidget(self.plot, 1, 0)

    mypen = pg.mkPen('y', width=1)
    self.curve = self.plot.plot(pen=mypen)

    # Plot
    self.t_plot_max = 30
    self.fe = 10e3
    self.t = np.arange(-1 * self.t_plot_max, 0, 1.0 / self.fe)
    self.len_signal = len(self.t)
    self.signal = np.zeros(self.len_signal, dtype=np.double)

    # status bar
    self.statusBar()

    # clicked button evt
    btnRandon.clicked.connect(self.buttonRandomClicked)

    # show graph
    self.show()

  #####################################################
  def mouseMoved(evt):
    mousePoint = self.curve.vb.mapSceneToView(evt[0])
    label.setText("<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (mousePoint.x(), mousePoint.y()))


  #####################################################
  def buttonRandomClicked(self):
    print ("Show/Hide OldB")
    self.signal = np.random.rand(20)
    self.curve.setData(self.signal)

#####################################################
  def update(self):
    proxy = pg.SignalProxy(self.curve.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
    self.statusBar().showMessage('Update timer event')

# MAIN ##################################################
def main():
  app = QtGui.QApplication(sys.argv)
  ex = TestClass()
  timer = QtCore.QTimer()
  timer.timeout.connect(ex.update)
  timer.start(200)
  sys.exit(app.exec_())


if __name__ == '__main__':
  main()

艾米知道我做错了什么吗？

谢谢。

Answer 1

没有必要使用QTimer 来执行此任务并创建一个名为update() 的方法，因为QMainWindow 具有类似的方法并且可能会干扰正确的操作。

每次移动鼠标都会发出sigMouseMoved信号，所以一般情况下不需要使用SignalProxy。

信号sigMouseMoved 返回相对于PlotWidget 的像素坐标，而不是绘图坐标，因此必须使用mapSceneToView 的mapSceneToView 方法进行转换@--> @ 987654330@ --> PlotWidget.

最后，不用GraphicsWindow()，这会创建另一个窗口，一个QWidget就够了。

import sys
from pyqtgraph.Qt import QtGui, QtCore
import numpy as np
import pyqtgraph as pg
import random

class TestClass(QtGui.QMainWindow):
    #####################################################
    def __init__(self):
        super(TestClass, self).__init__()
        self.initUI()
    ####################################################
    # GUI construction
    def initUI(self):
        self.setWindowTitle("Mouse Point, x & y")
        win = QtGui.QWidget()
        # creates plot
        self.plot = pg.PlotWidget()
        self.plot.setLabel('left', "B", units='T')
        self.plot.setLabel('bottom', "t", units='s')
        self.plot.showGrid(x=1, y=1, alpha=None)
        self.setCentralWidget(win)
        self.setGeometry(600, 600, 600, 600)
        self.setWindowTitle('Mouse Point, x& y GUI')

        # Create some widgets to be placed inside
        btnRandon = QtGui.QPushButton('Random Function')
        # Create a grid layout to manage the widgets size and position
        layout = QtGui.QGridLayout(win)

        # Add widgets to the layout in their proper positions
        layout.addWidget(btnRandon, 0, 0) # button to show or hide the OldB
        layout.addWidget(self.plot, 1, 0)

        mypen = pg.mkPen('y', width=1)
        self.curve = self.plot.plot(x=[], y=[], pen=mypen)

        # Plot
        self.t_plot_max = 30
        self.fe = 10e3
        self.t = np.arange(-1 * self.t_plot_max, 0, 1.0 / self.fe)
        self.len_signal = len(self.t)
        self.signal = np.zeros(self.len_signal, dtype=np.double)

        btnRandon.clicked.connect(self.buttonRandomClicked)
        self.curve.scene().sigMouseMoved.connect(self.onMouseMoved)

    def onMouseMoved(self, point):
        p = self.plot.plotItem.vb.mapSceneToView(point)
        self.statusBar().showMessage("{}-{}".format(p.x(), p.y()))

    def buttonRandomClicked(self):
        print ("Show/Hide OldB")
        self.signal = np.random.rand(20)
        self.curve.setData(self.signal)


# MAIN ##################################################
def main():
    app = QtGui.QApplication(sys.argv)
    ex = TestClass()
    ex.show()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

Answer 2

抱歉，我正在使用 PyQt5。试试看：

import sys

#from pyqtgraph.Qt import QtGui, QtCore     # ---
from PyQt5 import QtWidgets, QtGui, QtCore  # +++

import numpy as np
import pyqtgraph as pg
import time
import random

class TestClass(QtGui.QMainWindow):
  #####################################################
  def __init__(self):
    super(TestClass, self).__init__()
    self.num = 0                        ### +++
    self.initUI()

  #####################################################
  # GUI construction
  def initUI(self):
    win = pg.GraphicsWindow(title="Mouse Point, x & y")

    # creates plot
    self.plot = pg.PlotWidget()
    self.plot.setLabel('left', "B", units='T')
    self.plot.setLabel('bottom', "t", units='s')
    self.plot.showGrid(x=1, y=1, alpha=None)
    self.setCentralWidget(win)
    self.setGeometry(600, 600, 600, 600)
    self.setWindowTitle('Mouse Point, x& y GUI')

    # Create some widgets to be placed inside
    btnRandon = QtGui.QPushButton('Random Function')


    # Create a grid layout to manage the widgets size and position
    layout = QtGui.QGridLayout()
    win.setLayout(layout)

    # Add widgets to the layout in their proper positions
    layout.addWidget(btnRandon, 0, 0) # button to show or hide the OldB
    layout.addWidget(self.plot, 1, 0)

    mypen = pg.mkPen('y', width=1)
    self.curve = self.plot.plot(pen=mypen)

    # Plot
    self.t_plot_max = 30
    self.fe = 10e3
    self.t = np.arange(-1 * self.t_plot_max, 0, 1.0 / self.fe)
    self.len_signal = len(self.t)
    self.signal = np.zeros(self.len_signal, dtype=np.double)

    # status bar
    self.statusBar()

    # clicked button evt
    btnRandon.clicked.connect(self.buttonRandomClicked)

    # show graph
    self.show()

#  ### ------------------------------------------------
#  def mouseMoved(evt):
#    mousePoint = self.curve.vb.mapSceneToView(evt[0])
#    label.setText("<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (mousePoint.x(), mousePoint.y()))


  #####################################################
  def buttonRandomClicked(self):
    print ("Show/Hide OldB")
    self.signal = np.random.rand(20)
    self.curve.setData(self.signal)

#####################################################
#  def update(self):
#    proxy = pg.SignalProxy(self.curve.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
#    self.statusBar().showMessage('Update timer event')
### vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
  def update(self):
    ### +++++++++++++++++++++++++++++++++++++++++++++
    def mouseMoved(evt): 
      print("-->> def mouseMoved(evt):", evt)
      print("\tevt.x()=`{}`, evt.y()=`{}`".format(evt.x(), evt.y()))

      # AttributeError: 'PlotDataItem' object has no attribute 'vb'        ### ???????
      #mousePoint = self.curve.vb.mapSceneToView(evt[0])

      # vvvv - > label what is it? <-- NameError: name `label` is not defined ### ???????
      #label.setText("<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (mousePoint.x(), mousePoint.y()))


    self.source = self.curve.scene().sigMouseMoved
    #print(" source ", self.source)
    proxy = pg.SignalProxy(self.source, rateLimit=60, slot=mouseMoved) #+self
    #print("def update(self):222", proxy)
    if self.source is None:
        pass
        #sp.connect(sp, QtCore.SIGNAL('signal'), slot)
    else:
        #sp.connect(sp, signal, slot)
        proxy.signal.connect(mouseMoved)

    self.statusBar().showMessage('Update timer event `{}`'.format(self.num))
    self.num += 1    
    return proxy    



# MAIN ##################################################
def main():
  app = QtGui.QApplication(sys.argv)
  ex = TestClass()
  timer = QtCore.QTimer()
  timer.timeout.connect(ex.update)
  timer.start(200)
  sys.exit(app.exec_())


if __name__ == '__main__':
  main()