清除 Tkinter GUI 中每个选项卡的画布

Question

我有一个复杂的 gui，太长了，无法在此处发布。我无法理解如何从我的 Tkinter gui 中的图形中清除图形。我有一个选项卡式 gui，想在每个选项卡中绘制一个图形并清除每个选项卡中的图形。当我尝试这样做时，我会遇到与画布有关的各种不同错误。我可以理解图形、轴、选项卡和框架，但画布似乎被称为图形的同义词，看起来很奇怪（而且可能不正确）。

我看不出图形和画布之间有什么区别（有吗？），我在这里阅读的大多数文章和答案似乎根本没有覆盖画布

Matplotlib 文档： “数字 整个图。该人物跟踪所有子 Axes、少数“特殊”艺术家（标题、人物传说等）和画布。 （不要太担心画布，它是至关重要的，因为它是实际绘制绘图的对象，但作为用户，它是你或多或少看不见）。一个图形可以有任意数量的轴，但要有用，至少应该有一个。”

代码

import tkinter.filedialog
import os
import re
import tkinter as tk                     
from tkinter import ttk 
import matplotlib
matplotlib.use("TkAgg")  # this is the backend of matplotlib
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2Tk
from matplotlib.figure import Figure
import matplotlib.animation as animation
from matplotlib import style
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import easygui
from matplotlib.legend_handler import HandlerLine2D
from scipy.stats import linregress
pd.set_option("display.max_rows", None, "display.max_columns", None)

#=====================================================================
# ROOT FIGURE FOR GUI
#=====================================================================
root = tk.Tk() 
root.title("Tab Widget")
root.geometry("600x450") 
tabControl = ttk.Notebook(root) 
tab1 = ttk.Frame(tabControl) 
tab2 = ttk.Frame(tabControl)
tabControl.add(tab1, text ='Circle cal drops')
tabControl.add(tab2, text ='OPW') 

tk.Grid.rowconfigure(root, 0, weight=1)
tk.Grid.columnconfigure(root, 0, weight=1)
tabControl.grid(column=0, row=0, sticky=tk.E+tk.W+tk.N+tk.S)


# TAB 1
# creating a frame (my_frame_1)
my_frame_1 = tk.Frame(tab1, bd=2, relief=tk.GROOVE)
my_frame_1.pack(side=tk.LEFT, anchor=tk.N, fill=tk.BOTH, expand=True)
#---------------------------------------------------------------------

fig = Figure(figsize=(4,4), dpi=100)

def clearPlot():
    fig.clear()
    canvas.draw_idle()


def plotData():
    a = fig.add_subplot(111)
    a.plot([1, 2, 3, 4, 5], [5, 6, 1, 3, 8], marker='.', c='r')
    canvas = FigureCanvasTkAgg(fig, master = my_frame_1)
    canvas.get_tk_widget().pack()
    canvas._tkcanvas.pack()


#create another frame(my_frame_2) 
my_frame_2 = tk.Frame(tab1, bd=2, relief=tk.GROOVE)
my_frame_2.pack(side=tk.RIGHT)
#---------------------------------------------------------------------
button1_cal = tk.Button(my_frame_2, text = "Clear Plot", command = clearPlot, relief = tk.GROOVE, padx =20, pady =20 )
button1_cal.pack(side="top", fill="x")
button2_cal = tk.Button(my_frame_2, text = "Plot \nData", command = plotData, relief = tk.GROOVE, padx =20, pady =20 )
button2_cal.pack(side="top", fill="x" )

# TAB 2
# creating a frame (my_frame_3)
my_frame_3 = tk.Frame(tab2, bd=2, relief=tk.GROOVE)
my_frame_3.pack(side=tk.LEFT, anchor=tk.N, fill=tk.BOTH, expand=True)
#---------------------------------------------------------------------

def clearPlotOpw():
    pass

def plotDataOpw():
    fig = Figure(figsize=(4,4), dpi=100)
    a = fig.add_subplot(111)
    a.plot([1, 2, 3, 4, 5], [8, 5, 1, 3, 11], marker='o', c='b')

    canvas = FigureCanvasTkAgg(fig, master = my_frame_3)
    canvas.get_tk_widget().pack()

    canvas._tkcanvas.pack()

#create another frame(my_frame_4) 
my_frame_4 = tk.Frame(tab2, bd=2, relief=tk.GROOVE)
my_frame_4.pack(side=tk.RIGHT)

button1_cal = tk.Button(my_frame_4, text = "Clear Plot", command = clearPlotOpw, relief = tk.GROOVE, padx =20, pady =20 )
button1_cal.pack(side="top", fill="x")
button2_cal = tk.Button(my_frame_4, text = "Plot \nData", command = plotDataOpw, relief = tk.GROOVE, padx =20, pady =20 )
button2_cal.pack(side="top", fill="x" )

root.mainloop()
print('\n'*4)

*** 期望的结果 ***

能够根据需要清除每个绘图并重新绘图。

尝试使用清晰绘图功能时的回溯

Exception in Tkinter callback
Traceback (most recent call last):
  File "/Users/.../opt/anaconda3/lib/python3.7/tkinter/__init__.py", line 1705, in __call__
    return self.func(*args)
  File "/Users/.../Desktop/tk_gui_grid/basic_08.py", line 48, in clearPlot
    canvas.draw_idle()
NameError: name 'canvas' is not defined

我知道画布是未定义的，但是当我定义它时，情节根本没有被绘制出来。

Answer 1

这最终对我有用。

#MAKE A FIGURE OBJECT
my_figure4 = Figure(figsize = (4, 4), dpi = 100) 

#MAKE A FRAME WIDGET
frame1 = tk.Frame(tab4, bd=2, relief=tk.GROOVE)
frame1.pack(side=tk.LEFT, anchor=tk.N, fill=tk.BOTH, expand=True)
frame2 = tk.Frame(tab4, bd=2, relief=tk.GROOVE)
frame2.pack(side=tk.RIGHT)

#MAKE A CANVAS OBJECT
my_canvas4 = FigureCanvasTkAgg(my_figure4, master = frame1) # creating the Tkinter canvas containing the Matplotlib figure  

# TURN THE CANVAS OBJECT INTO A CANVAS WIDGET
my_canvas4.get_tk_widget().pack() # placing the canvas on the Tkinter window
my_canvas4.draw()

def plotData():
    plot1 = my_figure4.add_subplot(111) # adding the subplot 
    x = [1,2,3,4,5]
    y = [1, 2, 3, 4, 5]
    plot1.plot(x, y, marker='o', c='y')
    my_canvas4.draw()

def clearPlot():
    my_figure4.clear()
    my_canvas4.draw_idle()