PyQt5 结合 matplotlib 时，如何显示其 NavigationToolbar

〇、PyQt4 与 PyQt5 导入 NavigationToolbar 时的区别（去掉两个agg）

# PyQt4 版本（网传）
#from matplotlib.backends.backend_qt4agg import NavigationToolbar2QTAgg as NavigationToolbar

# PyQt5 版本
from matplotlib.backends.backend_qt5 import NavigationToolbar2QT as NavigationToolbar

一、隐藏 matplotlib 工具条

import sys
from PyQt5 import QtWidgets

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5 import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt

import random

class Window(QtWidgets.QDialog):
def __init__(self, parent=None):
super().__init__(parent)

self.figure = plt.figure()
self.axes = self.figure.add_subplot(111)
# We want the axes cleared every time plot() is called
self.axes.hold(False)
self.canvas = FigureCanvas(self.figure)

self.toolbar = NavigationToolbar(self.canvas, self)
self.toolbar.hide()

# Just some button
self.button1 = QtWidgets.QPushButton('Plot')
self.button1.clicked.connect(self.plot)

self.button2 = QtWidgets.QPushButton('Zoom')
self.button2.clicked.connect(self.zoom)

self.button3 = QtWidgets.QPushButton('Pan')
self.button3.clicked.connect(self.pan)

self.button4 = QtWidgets.QPushButton('Home')
self.button4.clicked.connect(self.home)

# set the layout
layout = QtWidgets.QVBoxLayout()
layout.addWidget(self.toolbar)
layout.addWidget(self.canvas)

btnlayout = QtWidgets.QHBoxLayout()
btnlayout.addWidget(self.button1)
btnlayout.addWidget(self.button2)
btnlayout.addWidget(self.button3)
btnlayout.addWidget(self.button4)
qw = QtWidgets.QWidget(self)
qw.setLayout(btnlayout)
layout.addWidget(qw)

self.setLayout(layout)

def home(self):
self.toolbar.home()
def zoom(self):
self.toolbar.zoom()
def pan(self):
self.toolbar.pan()

def plot(self):
''' plot some random stuff '''
data = [random.random() for i in range(25)]
self.axes.plot(data, '*-')
self.canvas.draw()

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

main = Window()
main.setWindowTitle('Simple QTpy and MatplotLib example with Zoom/Pan')
main.show()

sys.exit(app.exec_())

二、显示 matplotlib 工具条

import sys, os, random

from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

import matplotlib
matplotlib.use('Qt5Agg')
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5 import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure

class AppForm(QMainWindow):
def __init__(self, parent=None):
QMainWindow.__init__(self, parent)
self.setWindowTitle('Demo: PyQt with matplotlib')

self.create_menu()
self.create_main_frame()
self.create_status_bar()

self.textbox.setText('1 2 3 4')
self.on_draw()

def save_plot(self):
file_choices = "PNG (*.png)|*.png"

path = QFileDialog.getSaveFileName(self,
'Save file', '',
file_choices)
if path:
self.canvas.print_figure(path, dpi=self.dpi)
self.statusBar().showMessage('Saved to %s' % path, 2000)

def on_about(self):
msg = """ A demo of using PyQt with matplotlib:

* Use the matplotlib navigation bar
* Add values to the text box and press Enter (or click "Draw")
* Show or hide the grid
* Drag the slider to modify the width of the bars
* Save the plot to a file using the File menu
* Click on a bar to receive an informative message
"""
QMessageBox.about(self, "About the demo", msg.strip())

def on_pick(self, event):
# The event received here is of the type
# matplotlib.backend_bases.PickEvent
#
# It carries lots of information, of which we're using
# only a small amount here.
#
box_points = event.artist.get_bbox().get_points()
msg = "You've clicked on a bar with coords:\n %s" % box_points

QMessageBox.information(self, "Click!", msg)

def on_draw(self):
""" Redraws the figure
"""
#str = unicode(self.textbox.text())
self.data = list(map(int, self.textbox.text().split()))

x = range(len(self.data))

# clear the axes and redraw the plot anew
#
self.axes.clear()
self.axes.grid(self.grid_cb.isChecked())

self.axes.bar(
left=x,
height=self.data,
width=self.slider.value() / 100.0,
align='center',
alpha=0.44,
picker=5)

self.canvas.draw()

def create_main_frame(self):
self.main_frame = QWidget()

# Create the mpl Figure and FigCanvas objects.
# 5x4 inches, 100 dots-per-inch
#
self.dpi = 100
self.fig = Figure((5.0, 4.0), dpi=self.dpi)
self.canvas = FigureCanvas(self.fig)
self.canvas.setParent(self.main_frame)

# Since we have only one plot, we can use add_axes
# instead of add_subplot, but then the subplot
# configuration tool in the navigation toolbar wouldn't
# work.
#
self.axes = self.fig.add_subplot(111)

# Bind the 'pick' event for clicking on one of the bars
#
self.canvas.mpl_connect('pick_event', self.on_pick)

# Create the navigation toolbar, tied to the canvas
#
self.mpl_toolbar = NavigationToolbar(self.canvas, self.main_frame)

# Other GUI controls
#
self.textbox = QLineEdit()
self.textbox.setMinimumWidth(200)
self.textbox.editingFinished.connect(self.on_draw)

self.draw_button = QPushButton("&Draw")
self.draw_button.clicked.connect(self.on_draw)

self.grid_cb = QCheckBox("Show &Grid")
self.grid_cb.setChecked(False)
self.grid_cb.stateChanged.connect(self.on_draw) #int

slider_label = QLabel('Bar width (%):')
self.slider = QSlider(Qt.Horizontal)
self.slider.setRange(1, 100)
self.slider.setValue(20)
self.slider.setTracking(True)
self.slider.setTickPosition(QSlider.TicksBothSides)
self.slider.valueChanged.connect(self.on_draw)#int

#
# Layout with box sizers
#
hbox = QHBoxLayout()

for w in [  self.textbox, self.draw_button, self.grid_cb,
slider_label, self.slider]:
hbox.addWidget(w)
hbox.setAlignment(w, Qt.AlignVCenter)

vbox = QVBoxLayout()
vbox.addWidget(self.mpl_toolbar)
vbox.addWidget(self.canvas)
vbox.addLayout(hbox)

self.main_frame.setLayout(vbox)
self.setCentralWidget(self.main_frame)

def create_status_bar(self):
self.status_text = QLabel("This is a demo")
self.statusBar().addWidget(self.status_text, 1)

def create_menu(self):
self.file_menu = self.menuBar().addMenu("&File")

load_file_action = self.create_action("&Save plot",
shortcut="Ctrl+S", slot=self.save_plot,
tip="Save the plot")
quit_action = self.create_action("&Quit", slot=self.close,
shortcut="Ctrl+Q", tip="Close the application")

self.add_actions(self.file_menu,
(load_file_action, None, quit_action))

self.help_menu = self.menuBar().addMenu("&Help")
about_action = self.create_action("&About",
shortcut='F1', slot=self.on_about,
tip='About the demo')

self.add_actions(self.help_menu, (about_action,))

def add_actions(self, target, actions):
for action in actions:
if action is None:
target.addSeparator()
else:
target.addAction(action)

def create_action(  self, text, slot=None, shortcut=None,
icon=None, tip=None, checkable=False,
signal="triggered()"):
action = QAction(text, self)
if icon is not None:
action.setIcon(QIcon(":/%s.png" % icon))
if shortcut is not None:
action.setShortcut(shortcut)
if tip is not None:
action.setToolTip(tip)
action.setStatusTip(tip)
if slot is not None:
action.triggered.connect(slot)
if checkable:
action.setCheckable(True)
return action

def main():
app = QApplication(sys.argv)
form = AppForm()
form.show()
app.exec_()

if __name__ == "__main__":
main()