如何从 Tkinter 中的 matplotlib remove/clear 子图和 canvas（白色 window- FigureCanvasTkAgg）？

Question

我正在尝试运行一个提供两个按钮的图形用户界面。第一个是打印文件内容 'names.txt'，第二个是绘制数据。但是，如果我先绘制数据然后打印内容，则子图将保持原样，我无法清除它。这是我的输出：[![wrong_output][1]]1 我读了 post : 并尝试了同样的方法，但是我没有得到正确的输出次要情节并没有破坏。我什至尝试使用 self.scatter1.get_tk_widget().destroy() destroy 小部件，但这也不起作用有人可以告诉我如何进行吗？我的代码是：

import tkinter as tk
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import random

x_loc=[5, 6, 34, 54, 23]
y_loc=[3, 4.34, 2, 44, 65]
avgLst=[24, 35.65, 54.6, 53, 2]
root= tk.Tk()

class graph_plot():
    global graph_past
    global graph_Avg
    
    def __init__(self):
        self.figure1 = plt.Figure()
        self.scatter1 = FigureCanvasTkAgg(self.figure1, root)
        self.scatter1.get_tk_widget().place(relx= 0.5, rely=0.1)
        self.subplot1 = self.figure1.add_subplot(111)
        self.subplot1.set_xlabel('x location')
        self.subplot1.set_ylabel('y location')
        
        
    def display_graph(self):
        data1 = {'x-locations' : x_loc , 'y_locations' : y_loc}
        df3 = DataFrame(data1,columns=['x-locations','y_locations'])
        global graph_past
        label2.config(text='')
        print('graph in= ' , graph_past)
        im0= self.subplot1.scatter(df3['x-locations'],df3['y_locations'], c=avgLst, cmap='rainbow', vmin=min(avgLst), vmax=max(avgLst))
        self.figure1.colorbar(im0)
        self.subplot1.set_title('Avg')
        graph_past= True
            
    def clear_graph(self):
        print('Destroyed!')
        self.subplot1.clear
        ## ??? which command


def do_graph():
    obj1 = graph_plot()
    obj1.display_graph()
   
def on_key(event):
    if myLine and event.keysym != 'Return':
        update_print()

def do_printing():
    global myLine
    global graph_past
    #print('graph_past= ' , graph_past)
    if graph_past:
        obj2 = graph_plot()
        obj2.clear_graph()
    graph_past = False
    input_File = open('names.txt','r')
    myLine = input_File.readlines()
    update_print()
    
def update_print():
    label2.config(text=random.choice(myLine))
  
def flag_print():
    global graph_Avg
    graph_Avg=False
    do_printing()

def flag_Avg():
    global graph_Avg
    graph_Avg=True
    do_graph()

root.bind('<Key>', on_key)

myCanvas = tk.Canvas(root, width = 800, height = 500)
myCanvas.grid(row=2, column= 4)

label1 = tk.Label(root, text='MENU')
label1.config(font=('Arial', 20))
myCanvas.create_window(200, 20, window=label1)
myLine= None
graph_Avg=False
graph_past=False

label2 = tk.Label(root, font=('Courier', 15))
label2.place(relx= 0.3, rely=0.1)

B1 = tk.Button(root, text ="Option 1", font=('Courier', 12), command = flag_print)
myCanvas.create_window(200, 100, window=B1)

B2 = tk.Button(root, text ="Option 2", font=('Courier', 12), command = flag_Avg)
myCanvas.create_window(200, 140, window=B2)

root.mainloop()```


  [1]: https://i.stack.imgur.com/RgL7S.png

Answer 1

问题

问题是由于在 graph_plot class 的 __init__() 方法中创建了多个 FigureCanvasTkAgg 对象。此构造函数在 do_graph() 和 do_printing() 方法中调用，这意味着许多相同的 canvas 是在彼此之上创建的。这意味着当您 .destroy() 小部件时，它将破坏一个新的小部件并留下下面的小部件。

解决方案

如果您要继续使用 classes，解决方案是将更多变量提升到全局变量中，这样可以确保您处理的是相同的对象，而不是单独的对象.不过，最好重新考虑使用 classes 来解决这个问题。

代码我重组了您的一些代码以避开 classes 并获得预期的结果：

import tkinter as tk
import matplotlib.pyplot as plt
from pandas import DataFrame
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import random

x_loc=[5, 6, 34, 54, 23]
y_loc=[3, 4.34, 2, 44, 65]
avgLst=[24, 35.65, 54.6, 53, 2]

GRAPH_AVG=False
GRAPH_PAST=False
MY_LINE = None


ROOT = tk.Tk()
ROOT.geometry("900x600")
FIGURE = plt.Figure()
SCATTER = FigureCanvasTkAgg(FIGURE, ROOT)

TK_WIDGET = SCATTER.get_tk_widget()

SUBPLOT = FIGURE.add_subplot(111)
SUBPLOT.set_xlabel('x location')
SUBPLOT.set_ylabel('y location')

NAME_LABEL = tk.Label(ROOT, font=('Courier', 15))
NAME_LABEL.place(relx=0.3, rely=0.1)
        
def display_graph():
    global GRAPH_PAST, FIGURE, SUBPLOT

    data1 = {'x-locations' : x_loc , 'y_locations' : y_loc}
    df3 = DataFrame(data1, columns=['x-locations','y_locations'])
    NAME_LABEL.config(text='')
    print('graph past= ' , GRAPH_PAST)
    im0= SUBPLOT.scatter(df3['x-locations'],df3['y_locations'], c=avgLst, cmap='rainbow', vmin=min(avgLst), vmax=max(avgLst))
    FIGURE.colorbar(im0)
    SUBPLOT.set_title('Avg')
    TK_WIDGET.place(relx=0.3, rely=0.1)
    GRAPH_PAST= True
        
def clear_graph():
    global SUBPLOT, TK_WIDGET
    print('Destroyed!')
    SUBPLOT.clear()
    TK_WIDGET.place_forget()

   
def on_key(event):
    global MY_LINE
    if MY_LINE and event.keysym != 'Return':
        update_print()

def do_printing():
    global MY_LINE, GRAPH_AVG, GRAPH_PAST

    if GRAPH_PAST:
        clear_graph()
    GRAPH_PAST = False
    MY_LINE = ["john kenny", "maria rose", "sheena"]
    update_print()
    
def update_print():
    NAME_LABEL.config(text=random.choice(MY_LINE))
  
def flag_print():
    global GRAPH_AVG
    GRAPH_AVG=False
    do_printing()

def flag_Avg():
    global GRAPH_AVG
    GRAPH_AVG=True
    display_graph()


ROOT.bind('<Key>', on_key)

B1 = tk.Button(ROOT, text ="Print", font=('Courier', 12), command=flag_print)
B1.place(relx=0.1, rely=0.1)

B2 = tk.Button(ROOT, text ="Graph", font=('Courier', 12), command=flag_Avg)
B2.place(relx=0.1, rely=0.2)

ROOT.mainloop()

Answer 2

尝试用 self.subplot1.clear() 代替 self.subplot1.destroy()

如何从 Tkinter 中的 matplotlib remove/clear 子图和 canvas（白色 window- FigureCanvasTkAgg）？

How to remove/clear the subplot and canvas (white window- FigureCanvasTkAgg) from matplotlib in Tkinter?

python

tkinter

matplotlib

python-3.x

subplot