在Pyqt中嵌入Matplotlib画布的实例 - 阴谋没有显示

Question

我试图尽量缩短范例。有一个similar question on SO。与上述问题提供的答案相反，我想定义一个MatplotlibFigure类，以便我可以重用代码。我在函数make_tab1中添加了对图的实例的引用self.figure = MatplotlibFigure()，并将self.figure添加到splitter。按钮似乎工作，因为我可以使用导航工具栏保存图形。但是，该轴没有显示在GUI中。

为什么轴不可见？

import sys 
from PyQt5.QtWidgets import QMainWindow, QApplication, QPushButton, QWidget, QAction, QTabWidget, QVBoxLayout,\ 
          QHBoxLayout, QGridLayout, QSplitter, QFrame, QTextEdit, QFileDialog, QGroupBox,\ 
          QButtonGroup, QLabel, QRadioButton 

from PyQt5 import QtCore 

import matplotlib 
from matplotlib import figure 
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas 
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar 

class MatplotlibFigure(QWidget): 

    # constructor 
    def __init__(self): 
     super().__init__() 
     #self.layout = QBoxLayout() 
     self.figure = matplotlib.figure.Figure() 
     self.canvas = FigureCanvas(self.figure) 
     self.toolbar = NavigationToolbar(self.canvas, self) 
     #self.layout.addWidget(self.canvas) 

    def plot(self): 
     self.figure.clf() 
     ax = self.figure.add_subplot(111) 
     x = [i for i in range(100)] 
     y = [i**0.5 for i in x] 
     ax.plot(x, y, 'g*-') 
     self.canvas.draw_idle() 
     print('PLOTTED') 


class MainApp(QMainWindow): 
    """ This creates the main Window and configures its look 
    """ 
    def __init__(self): 
     ''' 
     Initializes the class with standard parameters 
     ''' 
     super().__init__() 
     self.title = 'Data Analysis App' 

     # start at top left corner of the screen 
     self.left = 0 
     self.top = 0 

     # set the window height and width 
     self.width = 1280 
     self.height = 780 

     # set the styles of fonts etc. 
     self.setStyleSheet('font-size: 16pt') 

     # call the makeUI method 
     self.makeUI() 

    def makeUI(self): 
     # set window geometry 
     self.setWindowTitle(self.title) 
     self.setGeometry(self.left, self.top, self.width, self.height) 

     # generate the tab layout 
     self.table_widget = MyTableWidget() 
     self.setCentralWidget(self.table_widget) 

     # apparently we have to call the show method in order to show it 
     self.show() 


class MyTableWidget(QWidget): 
    """ 
    Initializes the tab layout 
    """ 

    def __init__(self): 
     super().__init__() 
     self.layout = QVBoxLayout(self) 

     # initialize the tab screens 
     self.tabs = QTabWidget() 

     # add the tab screens to the tab widget 
     self.tabs.resize(600, 600) 

     # make the layout of the tabs 
     self.make_tab1() 

     # initialize the tabs 
     self.layout.addWidget(self.tabs) 
     self.setLayout(self.layout) 

    def make_tab1(self): 
     """Style of tab 1 is created here""" 

     '''Defines master layout of tab1''' 
     tab1 = QWidget() 
     tab1.layout = QHBoxLayout() 

     '''Button Section''' 

     # converts the data into excel and pandas dataframe 
     btn_plot_data = QPushButton('Plot data') 
     btn_plot_data.clicked.connect(self.plot_data) 


     '''Button layout section''' 
     btn_layout = QVBoxLayout() 
     btn_layout.addWidget(btn_plot_data) 
     btn_layout.addStretch(1) 

     '''Page layout section ''' 

     left = QFrame() 
     left.setLayout(btn_layout) 

     self.figure = MatplotlibFigure() 

     # combine the buttons and the canvas in a splitter layout 
     splitter1 = QSplitter(QtCore.Qt.Horizontal) 
     splitter1.addWidget(left) 
     splitter1.addWidget(self.figure) 
     splitter1.setSizes([5, 400]) 


     # add the last splitter to the layout 
     tab1.layout.addWidget(splitter1) 
     tab1.setLayout(tab1.layout) 
     self.tabs.addTab(tab1, 'Get Data Module') 

    ''' Methods section 
    ''' 
    def plot_data(self): 
     self.figure.plot() 


if __name__ == '__main__': 
    """ This code block is always the same and makes sure that e.g. STRG+C kills the window etc. 
    """ 
    app = QApplication(sys.argv) 
    ex = MainApp() 
    sys.exit(app.exec()) 

Answer 1

你忘了你的MatplotlibFigure类设置布局（记住，这是一个QWidget你的情况，不画布）

def __init__(self): 
    super().__init__() 
    #self.layout = QBoxLayout() 
    self.figure = matplotlib.figure.Figure() 
    self.canvas = FigureCanvas(self.figure) 
    self.toolbar = NavigationToolbar(self.canvas, self) 

    layout = QVBoxLayout(self) 
    layout.addWidget(self.toolbar) 
    layout.addWidget(self.canvas) 

Answer 2

您需要家长设置为FigureCanvas：

self.canvas.setParent(self)