如何将我的Matplotlib图嵌入到Tkinter GUI中

Question

我一直在搞乱Tkinter和嵌入式图，并且从网上找到的教程中，我已经能够使以下代码段完美地工作：

from tkinter import *
import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg # NavigationToolbar2TkAgg
from matplotlib.figure import Figure 

root = Tk()

# Typical matplotlib code

f = Figure(figsize = (4,3), dpi = 100)
a = f.add_subplot(111)
a.plot([1,2,4,3,5,7,6,7,8,8,9,6,7,8,7,5,6,4,3,4,3,2,1])

canvas = FigureCanvasTkAgg(f, root)
canvas.draw()
canvas.get_tk_widget().pack()
canvas._tkcanvas.pack()

root.mainloop()

问题是我无法将其整合到我正在研究的程序中（Collat​​z猜想算法）。 我想做的是绘制一个迭代数据点的图形，但是该图形不显示，尽管我脚本中的代码的相关部分与示例代码段相同。 请参阅下面的代码：

#!/usr/local/bin/env python3
# -*- coding: utf-8 -*-

from tkinter import *
from tkinter import messagebox

root=Tk()
root.title("Collatz  Conjecture")

import textwrap

# Matplotlib imports

import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg # NavigationToolbar2TkAgg
from matplotlib.figure import Figure 


 # Functions

lst = []

def collatz(num):
    lst.clear()
    while num != 1:
        lst.append(num)

        if num % 2 == 0:
            num = int(num / 2)

        else:
            num = int(3 * num + 1)

def main(event):
    num = int(input.get())

    collatz(num)


    output1.delete(1.0, END)
    output1.insert(END, lst)
    output2.delete(1.0, END)
    output2.insert(END, "Number of iterations: " + str(len(lst)))



lbl1 = Label(root, width = 20, text = "Type in number\n & press Enter")
lbl1.grid(row = 1, column = 0, sticky = W)
lbl2 = Label(root, width = 40, text = "THE COLLATZ CONJECTURE")
lbl2.grid(row = 4, column = 0)

input = Entry(root, width = 20, bg = "light grey")
input.grid(row = 1, padx = 6, sticky = E)
input.get()
input.bind("<Return>", main)

# Matplotlib Graph - typical code

f = Figure(figsize = (4,3), dpi = 100)                  # Create the figure
a = f.add_subplot(111)                                  # Add subplot
a.plot(lst)
                                            # Plot data in background

# Canvas
canvas = FigureCanvasTkAgg(f, root)
canvas.draw()
canvas.get_tk_widget().grid(row = 6, column = 0)         
canvas._tkcanvas.grid(row = 6, column = 0)

# canvas = Canvas(root, width= 350, height= 350, bg = "white")
# canvas.grid(row = 6, column = 0, padx = (5,5), pady = (5,5))

bt1 = Button(root, width = 10, text = "About")
bt1.grid(row = 7, column = 0, pady = (5,7))

output1 = Text(root, wrap = WORD, width = 50, height = 7, bg =   "light grey")  # Note word wrap attribute
output1.grid(row = 3, column = 0, padx = (5,1), sticky = W)
output2 = Text(root, width = 50, height = 1, bg = "white")
output2.grid(row = 2, column = 0, sticky = W)


def about():

    messagebox.showinfo("About", "The Collatz conjecture states that if you pick any positive whole number, and if its even, you divide it by two and if its odd, you multiply it by three and add one, and if you repeat this procedure often enough, the number that you started with will eventually reduce to one and if you play this game for long enough, your friends will eventually stop calling to see if you want to hang out ")

btn1 = Button(root, text = "About", command = about)
btn1.grid(row = 7, column = 0, pady = (5,7))


root.mainloop()

我很确定这是一个缩进问题，当有人指出我的新手错误时，我将感到非常尴尬，但是我试图以各种可能的方式来移动代码，但没有成功。

有人可以看看一下，不仅告诉我哪里出了问题，而且更重要的是，为什么会出错。

Answer 1

这个问题是根本的。 您的tkinter窗口循环会不断刷新绘图画布，因此您不会看到数据。 相反，您可以做的是将画布从窗口循环中移出并将其粘贴在main函数中。

显然还有其他/更好的解决方案，但我希望这一解决方案能突出您所面临的问题。

# -*- coding: utf-8 -*-

from tkinter import *
from tkinter import messagebox

root=Tk()
root.title("Collatz  Conjecture")

import textwrap

# Matplotlib imports

import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg # NavigationToolbar2TkAgg
from matplotlib.figure import Figure 


 # Functions

lst = []

def collatz(num):
    lst.clear()
    while num != 1:
        lst.append(num)

        if num % 2 == 0:
            num = int(num / 2)

        else:
            num = int(3 * num + 1)

def main(event):
    num = int(inp_ut.get())

    collatz(num)


    output1.delete(1.0, END)
    output1.insert(END, lst)
    output2.delete(1.0, END)
    output2.insert(END, "Number of iterations: " + str(len(lst)))
    # Generate the data and populate the canvas once. 
    f = Figure(figsize = (4,3), dpi = 100)                  # Create the figure
    a = f.add_subplot(111)                                  # Add subplot
    a.plot(lst)
    canvas = FigureCanvasTkAgg(f, root)
    canvas.draw()
    canvas.get_tk_widget().grid(row = 6, column = 0)         
    canvas._tkcanvas.grid(row = 6, column = 0)


lbl1 = Label(root, width = 20, text = "Type in number\n & press Enter")
lbl1.grid(row = 1, column = 0, sticky = W)
lbl2 = Label(root, width = 40, text = "THE COLLATZ CONJECTURE")
lbl2.grid(row = 4, column = 0)

inp_ut = Entry(root, width = 20, bg = "light grey")
inp_ut.grid(row = 1, padx = 6, sticky = E)
inp_ut.get()
inp_ut.bind("<Return>", main)

# Canvas
# canvas = Canvas(root, width= 350, height= 350, bg = "white")
# canvas.grid(row = 6, column = 0, padx = (5,5), pady = (5,5))

bt1 = Button(root, width = 10, text = "About")
bt1.grid(row = 7, column = 0, pady = (5,7))

output1 = Text(root, wrap = WORD, width = 50, height = 7, bg =   "light grey")  # Note word wrap attribute
output1.grid(row = 3, column = 0, padx = (5,1), sticky = W)
output2 = Text(root, width = 50, height = 1, bg = "white")
output2.grid(row = 2, column = 0, sticky = W)


def about():

    messagebox.showinfo("About", "The Collatz conjecture states that if you pick any positive whole number, and if its even, you divide it by two and if its odd, you multiply it by three and add one, and if you repeat this procedure often enough, the number that you started with will eventually reduce to one and if you play this game for long enough, your friends will eventually stop calling to see if you want to hang out ")

btn1 = Button(root, text = "About", command = about)
btn1.grid(row = 7, column = 0, pady = (5,7))


root.mainloop()