在PyQt5中绘制多图时添加滚动条以保留matplotlib图表原始尺寸的咨询

要实现带滚动条的多图表展示，你需要借助QScrollArea控件承载所有画布，同时修正原代码中多画布共用同个figure的问题，完整可运行代码如下：

import sys
import pandas as pd
import numpy as np

from PyQt5.QtWidgets import (
    QApplication,
    QMainWindow,
    QPushButton,
    QVBoxLayout,
    QWidget,
    QScrollArea # 新增滚动区域控件
)

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
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__()
        # 每个画布绑定独立figure，避免内容互相覆盖
        self.figure1 = plt.figure(figsize=(45,15))    
        self.canvas = FigureCanvas(self.figure1)
        self.figure2 = plt.figure(figsize=(45,15))
        self.canvas2 = FigureCanvas(self.figure2)
        self.figure3 = plt.figure(figsize=(45,15))
        self.canvas3 = FigureCanvas(self.figure3)

        # 外层主布局
        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)

        # 构建滚动区域
        scroll_area = QScrollArea()
        scroll_area.setWidgetResizable(False) # 关闭自动缩放，保留画布原始尺寸
        # 滚动区域内部承载所有画布的容器部件
        content_widget = QWidget()
        content_layout = QVBoxLayout(content_widget)
        # 把所有画布添加到内部容器布局
        content_layout.addWidget(self.canvas)
        content_layout.addWidget(self.canvas2)
        content_layout.addWidget(self.canvas3)
        # 绑定容器到滚动区域
        scroll_area.setWidget(content_widget)
        # 滚动区域添加到主布局
        layout.addWidget(scroll_area)

        self.setLayout(layout)

    def close_window(self):
        self.close()

    def plot(self):
        # 每个独立figure分别绘图
        self.figure1.clear()
        ax1 =  self.figure1.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax1)
        self.canvas.draw()

        self.figure2.clear()
        ax2 =  self.figure2.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax2)
        self.canvas2.draw()

        self.figure3.clear()
        ax3 =  self.figure3.add_subplot(111)
        data = pd.DataFrame(np.random.rand(5))
        data.plot(ax=ax3)
        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()

核心改动说明 #

• 新增QScrollArea作为滚动容器：所有图表画布放在滚动区域内部的子部件中，当画布总高度超出窗口显示范围时自动出现滚动条，不会压缩画布尺寸。
• 每个画布绑定独立figure：原代码中3个画布共用同一个figure会导致绘图内容互相覆盖，修改后每个画布对应独立的figure，完全保留设置的figsize原始尺寸。
• 布局结构调整：按钮固定在窗口顶部不随滚动条移动，滚动区域占满剩余窗口空间，符合常规使用习惯。

内容的提问来源于stack exchange，提问作者wwj123