python - 如果 pyqtgraph 在 GUI 中，则它没有交互模式

Question

不幸的是，我的 pyqtgraph 和由 QtDesigner 的 .ui 文件制作的最小 GUI 遇到了问题:

如果我运行此代码，其中包含 GUI 代码和 pyqtgraph-code-examples 之一(以行开头:# -*-coding: utf-8 -*-):

# Form implementation generated from reading ui file 'bspcode.ui'
#
# Created by: PyQt4 UI code generator 4.11.4
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName(_fromUtf8("Dialog"))
        Dialog.resize(400, 300)
        self.buttonBox = QtGui.QDialogButtonBox(Dialog)
        self.buttonBox.setGeometry(QtCore.QRect(30, 240, 341, 32))
        self.buttonBox.setOrientation(QtCore.Qt.Horizontal)
        self.buttonBox.setStandardButtons(QtGui.QDialogButtonBox.Cancel|QtGui.QDialogButtonBox.Ok)
        self.buttonBox.setObjectName(_fromUtf8("buttonBox"))
        self.verticalLayoutWidget = QtGui.QWidget(Dialog)
        self.verticalLayoutWidget.setGeometry(QtCore.QRect(9, 0, 381, 221))
        self.verticalLayoutWidget.setObjectName(_fromUtf8("verticalLayoutWidget"))
        self.verticalLayout = QtGui.QVBoxLayout(self.verticalLayoutWidget)
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.pushButton1 = QtGui.QPushButton(self.verticalLayoutWidget)
        self.pushButton1.setObjectName(_fromUtf8("pushButton1"))
        self.verticalLayout.addWidget(self.pushButton1)
        self.pushButton2 = QtGui.QPushButton(self.verticalLayoutWidget)
        self.pushButton2.setObjectName(_fromUtf8("pushButton2"))
        self.verticalLayout.addWidget(self.pushButton2)

        self.retranslateUi(Dialog)
        QtCore.QObject.connect(self.buttonBox, QtCore.SIGNAL(_fromUtf8("accepted()")), Dialog.accept)
        QtCore.QObject.connect(self.buttonBox, QtCore.SIGNAL(_fromUtf8("rejected()")), Dialog.reject)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(_translate("Dialog", "Dialog", None))
        self.pushButton1.setText(_translate("Dialog", "PushButton", None))
        self.pushButton2.setText(_translate("Dialog", "PushButton", None))
# -*- coding: utf-8 -*-
"""
Various methods of drawing scrolling plots.
"""
#import initExample ## Add path to library (just for examples; you do not need this)

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

win = pg.GraphicsWindow()
win.setWindowTitle('pyqtgraph example: Scrolling Plots')


# 1) Simplest approach -- update data in the array such that plot appears to scroll
#    In these examples, the array size is fixed.
p1 = win.addPlot()
p2 = win.addPlot()
data1 = np.random.normal(size=300)
curve1 = p1.plot(data1)
curve2 = p2.plot(data1)
ptr1 = 0
def update1():
    global data1, curve1, ptr1
    data1[:-1] = data1[1:]  # shift data in the array one sample left
                            # (see also: np.roll)
    data1[-1] = np.random.normal()
    curve1.setData(data1)

    ptr1 += 1
    curve2.setData(data1)
    curve2.setPos(ptr1, 0)


# 2) Allow data to accumulate. In these examples, the array doubles in length
#    whenever it is full. 
win.nextRow()
p3 = win.addPlot()
p4 = win.addPlot()
# Use automatic downsampling and clipping to reduce the drawing load
p3.setDownsampling(mode='peak')
p4.setDownsampling(mode='peak')
p3.setClipToView(True)
p4.setClipToView(True)
p3.setRange(xRange=[-100, 0])
p3.setLimits(xMax=0)
curve3 = p3.plot()
curve4 = p4.plot()

data3 = np.empty(100)
ptr3 = 0

def update2():
    global data3, ptr3
    data3[ptr3] = np.random.normal()
    ptr3 += 1
    if ptr3 >= data3.shape[0]:
        tmp = data3
        data3 = np.empty(data3.shape[0] * 2)
        data3[:tmp.shape[0]] = tmp
    curve3.setData(data3[:ptr3])
    curve3.setPos(-ptr3, 0)
    curve4.setData(data3[:ptr3])


# 3) Plot in chunks, adding one new plot curve for every 100 samples
chunkSize = 100
# Remove chunks after we have 10
maxChunks = 10
startTime = pg.ptime.time()
win.nextRow()
p5 = win.addPlot(colspan=2)
p5.setLabel('bottom', 'Time', 'sekunden')
p5.setXRange(-10, 0)
curves = []
data5 = np.empty((chunkSize+1,2))
ptr5 = 0

def update3():
    global p5, data5, ptr5, curves
    now = pg.ptime.time()
    for c in curves:
        c.setPos(-(now-startTime), 0)

    i = ptr5 % chunkSize
    if i == 0:
        curve = p5.plot()
        curves.append(curve)
        last = data5[-1]
        data5 = np.empty((chunkSize+1,2))        
        data5[0] = last
        while len(curves) > maxChunks:
            c = curves.pop(0)
            p5.removeItem(c)
    else:
        curve = curves[-1]
    data5[i+1,0] = now - startTime
    data5[i+1,1] = np.random.normal()
    curve.setData(x=data5[:i+2, 0], y=data5[:i+2, 1])
    ptr5 += 1


# update all plots
def update():
    update1()
    update2()
    update3()
timer = pg.QtCore.QTimer()
timer.timeout.connect(update)
timer.start(50)



## Start Qt event loop unless running in interactive mode or using pyside.
# if __name__ == '__main__':
    # import sys
    # if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        # QtGui.QApplication.instance().exec_()


if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    sys.exit(app.exec_())

GUI 和绘图窗口都会启动并运行，但绘图不是交互式的，因为我会独立运行 pyqtgraph-example-code。

我猜这是因为评论了这段代码:

## Start Qt event loop unless running in interactive mode or using pyside.
# if __name__ == '__main__':
    # import sys
    # if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        # QtGui.QApplication.instance().exec_()

但是，如果我取消注释此行，绘图窗口将以交互模式启动，但在关闭绘图窗口之前，我的 GUI 窗口不会显示。

如何让它们(GUI 和绘图窗口)在交互模式下与绘图窗口同时显示？

有什么建议吗？

Answer 1

为了让 PyQt 小部件正常工作，它们需要在创建小部件之前创建一个 QApplication，在这种情况下，您之前没有任何 pg.GraphicsWindow() >。解决办法是:

...
import sys # <---

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

app = QtGui.QApplication(sys.argv) # <---
win = pg.GraphicsWindow()
...


if __name__ == "__main__":
    if not QtGui.QApplication.instance(): # <---
        app = QtGui.QApplication(sys.argv) # <---
    Dialog = QtGui.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'): # <---
        sys.exit(QtGui.QApplication.instance().exec_()) # <---