如何让Matplotlib图表随Tkinter主窗口大小自适应？

要让你的Matplotlib图表随主窗口调整大小自动缩放，需要补充以下几处代码逻辑：

关键修改点 #

• 配置Tkinter网格布局权重，让承载图表的Notebook组件能随窗口拉伸
• 给图表画布绑定尺寸变化事件，监听窗口缩放动作
• 实现自适应回调函数，根据新画布尺寸调整图表大小并重新绘制

修改后的完整代码 #

import tkinter as tk
from tkinter import ttk

import os

import matplotlib.pyplot as plt

from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import pandas as pd


class AppWindow(tk.Tk):

    def __init__(self):
        super().__init__()
        self.notebook = None
        self.df = None
        self.df_1 = None
        self.build_app_window()

    def build_app_window(self):
        self.title("env_viewer")

        btn_refresh = tk.Button(self,
                                text="Aktualisieren",
                                command=self.refresh)
        btn_refresh.grid(row=3, column=0, sticky="new", padx=5)
        
        # 配置主窗口网格权重，让Notebook所在区域随窗口拉伸
        self.grid_columnconfigure(1, weight=1)
        self.grid_rowconfigure(2, weight=1)
        
        self.notebook = ttk.Notebook(self)
        self.notebook.grid(row=2, column=1, rowspan=10, sticky="nsew")

        self.add_voltage_tab()

    def add_voltage_tab(self):
        # 创建Figure，无需固定尺寸，后续自适应调整
        self.fig_voltage, self.ax_voltage = plt.subplots(dpi=100)
        # 生成Matplotlib画布
        self.canvas_voltage = FigureCanvasTkAgg(self.fig_voltage, master=self.notebook)
        canvas_widget = self.canvas_voltage.get_tk_widget()
        # 设置画布填充父容器并允许扩展
        canvas_widget.pack(fill=tk.BOTH, expand=True)
        # 绑定画布尺寸变化事件到缩放回调
        canvas_widget.bind('<Configure>', self.on_voltage_canvas_resize)
        
        self.notebook.add(canvas_widget, text='Spannung')

    def on_voltage_canvas_resize(self, event):
        # 通过DPI转换，将画布像素尺寸转为Figure英寸尺寸
        new_width = event.width / self.fig_voltage.dpi
        new_height = event.height / self.fig_voltage.dpi
        # 更新Figure尺寸
        self.fig_voltage.set_size_inches(new_width, new_height)
        # 仅当数据已加载时重绘图表
        if self.df is not None:
            self.update_voltage_plot()

    def update_voltage_plot(self):
        dates = self.df['Date Time']
        voltage = self.df['Voltage[V]']
        
        self.ax_voltage.clear()
        self.ax_voltage.plot(dates, voltage, color="blue", label="Spannung [V]")
        self.ax_voltage.legend(loc='upper left')
        self.fig_voltage.autofmt_xdate(rotation=45)
        self.fig_voltage.tight_layout()
        self.canvas_voltage.draw()

    def refresh(self):
        dir_path = os.path.dirname(os.path.realpath(__file__))
        self.filepath_1 = os.path.join(dir_path, "2023-07_environment_data.csv")
        self.df_1 = pd.read_csv(str(self.filepath_1), sep=';')
        self.update_df()
        self.update_voltage_plot()

    def update_df(self):
        self.df = self.df_1
        self.df['Date Time'] = pd.to_datetime(self.df['Date Time'])
        self.df = self.df.sort_values(by='Date Time')


if __name__ == "__main__":
    MainWindow = AppWindow()
    MainWindow.mainloop()

补充说明 #

• 网格权重设置确保Notebook能占据主窗口的可用空间，随窗口大小变化自动拉伸
• <Configure>事件会在画布尺寸改变时触发回调，通过DPI转换避免图表缩放后模糊
• 增加self.df is not None判断，防止窗口初始化阶段还未加载数据就触发重绘报错

内容的提问来源于stack exchange，提问作者Stefan