绘制多个图形时添加滚动条以在 PyQt5 中保留图形大小

Question

我正在尝试在 pyqt5 窗口小部件中绘制多个图形。我能够做到这一点，但如果我在窗口中添加更多图形，图形的大小只会被“压缩”。通过运行下面的代码并单击 Push for Window 1 与 Push for Window 2 来查看比较。

我想在canvas 中添加一个滚动条，这样我就可以保留图形的大小，就像将多个图形放在一个 word 文件中并使用滚动条上下移动来查看图形一样。我该怎么做？

import sys
import pandas as pd
import numpy as np

from PyQt5.QtWidgets import (
    QApplication,
    QLabel,
    QMainWindow,
    QPushButton,
    QVBoxLayout,
    QWidget,
)

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

class AnotherWindow1(QWidget):


    def __init__(self):
        super().__init__()
        self.figure = plt.figure(figsize=(45,15))    
        self.canvas = FigureCanvas(self.figure)  
        layout = QVBoxLayout()
        button1 = QPushButton("Plot")
        button1.clicked.connect(self.plot)
        button2 = QPushButton("Back")
        button2.clicked.connect(self.close_window)
        layout.addWidget(button1)
        layout.addWidget(button2)
        layout.addWidget(self.canvas)
        self.setLayout(layout)

    def close_window(self):
        self.close()

    def plot(self):
        self.figure.clear()
        ax1 =  self.figure.add_subplot(111) 
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax1)
        self.canvas.draw()

class AnotherWindow2(QWidget):


    def __init__(self):
        super().__init__()
        self.figure = plt.figure(figsize=(45,15))    
        self.canvas = FigureCanvas(self.figure)  
        self.canvas2 = FigureCanvas(self.figure) 
        self.canvas3 = FigureCanvas(self.figure)  
        layout = QVBoxLayout()
        button1 = QPushButton("Plot")
        button1.clicked.connect(self.plot)
        button2 = QPushButton("Back")
        button2.clicked.connect(self.close_window)
        layout.addWidget(button1)
        layout.addWidget(button2)
        layout.addWidget(self.canvas)
        layout.addWidget(self.canvas2)
        layout.addWidget(self.canvas3)
        self.setLayout(layout)

    def close_window(self):
        self.close()

    def plot(self):
        self.figure.clear()
        ax1 =  self.figure.add_subplot(111) 
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax1)
        self.canvas.draw()
        ax2 =  self.figure.add_subplot(111) 
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax2)
        self.canvas2.draw()
        ax2 =  self.figure.add_subplot(111) 
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax2)
        self.canvas3.draw()

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.window1 = AnotherWindow1()
        self.window2 = AnotherWindow2()

        l = QVBoxLayout()
        button1 = QPushButton("Push for Window 1")
        button1.clicked.connect(self.show_window1)
        l.addWidget(button1)

        button2 = QPushButton("Push for Window 2")
        button2.clicked.connect(self.show_window2)
        l.addWidget(button2)

        w = QWidget()
        w.setLayout(l)
        self.setCentralWidget(w)

    def show_window1(self):
        self.window1.show()

    def show_window2(self):
        self.window2.show()


app = QApplication(sys.argv)
w = MainWindow()
w.show()
app.exec()

Answer 1

您必须使用包含 QWidget 的 QScrollArea 作为画布的容器

import sys
import pandas as pd
import numpy as np

from PyQt5.QtWidgets import (
    QApplication,
    QLabel,
    QMainWindow,
    QPushButton,
    QScrollArea,
    QVBoxLayout,
    QWidget,
)

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure


class AnotherWindow1(QWidget):
    def __init__(self):
        super().__init__()

        self.figure = Figure(figsize=(45, 15))
        self.canvas = FigureCanvas(self.figure)

        button1 = QPushButton("Plot")
        button1.clicked.connect(self.plot)
        button2 = QPushButton("Back")
        button2.clicked.connect(self.close_window)

        layout = QVBoxLayout(self)
        layout.addWidget(button1)
        layout.addWidget(button2)
        layout.addWidget(self.canvas)

    def close_window(self):
        self.close()

    def plot(self):
        self.figure.clear()
        ax1 = self.figure.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax1)
        self.canvas.draw()


class AnotherWindow2(QWidget):
    def __init__(self):
        super().__init__()
        self.figure = Figure(figsize=(45, 15))

        self.canvas = FigureCanvas(self.figure)
        self.canvas.setMinimumSize(640, 480)
        self.canvas2 = FigureCanvas(self.figure)
        self.canvas2.setMinimumSize(640, 480)
        self.canvas3 = FigureCanvas(self.figure)
        self.canvas3.setMinimumSize(640, 480)

        canvas_scrollarea = QScrollArea(widgetResizable=True)
        canvas_container = QWidget()
        canvas_scrollarea.setWidget(canvas_container)
        canvas_layout = QVBoxLayout(canvas_container)
        canvas_layout.addWidget(self.canvas)
        canvas_layout.addWidget(self.canvas2)
        canvas_layout.addWidget(self.canvas3)

        button1 = QPushButton("Plot")
        button1.clicked.connect(self.plot)
        button2 = QPushButton("Back")
        button2.clicked.connect(self.close_window)

        layout = QVBoxLayout(self)

        layout.addWidget(button1)
        layout.addWidget(button2)
        layout.addWidget(canvas_scrollarea)

    def close_window(self):
        self.close()

    def plot(self):
        self.figure.clear()
        ax1 = self.figure.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax1)
        self.canvas.draw()
        ax2 = self.figure.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax2)
        self.canvas2.draw()
        ax2 = self.figure.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax2)
        self.canvas3.draw()


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.window1 = AnotherWindow1()
        self.window2 = AnotherWindow2()

        button1 = QPushButton("Push for Window 1")
        button1.clicked.connect(self.show_window1)

        button2 = QPushButton("Push for Window 2")
        button2.clicked.connect(self.show_window2)

        w = QWidget()
        l = QVBoxLayout(w)
        l.addWidget(button1)
        l.addWidget(button2)
        self.setCentralWidget(w)

    def show_window1(self):
        self.window1.show()

    def show_window2(self):
        self.window2.show()


app = QApplication(sys.argv)
w = MainWindow()
w.show()
app.exec()