如何使用“提取”作为在“ tkinter”中移动对象的输入？

Question

I am trying to make a replica of dodger using python. In my code, I made a window using tkinter . I tried to use getch() as a way of inputting arrow key values to make the main character move. Here is my code:

from tkinter import *
from msvcrt import getch
import time


class Window(Frame):
    def __init__(self, master=None):
        Frame.__init__(self, master)

        self.master = master
        self.initWindow()


    def initWindow(self):
        self.master.title('Dodger')
        self.pack(fill=BOTH, expand=1)
        self.master.geometry('600x800')
        self.master.config(bg='black')

        menu = Menu(self.master)
        self.master.config(menu=menu)

        def clientExit():
            exit()

        file = Menu(menu)
        file.add_command(label='Exit', command=clientExit)
        file.add_command(label='Start', command=self.game)

        menu.add_cascade(label='File', menu=file)


    def game(self):
        canvas = Canvas(self.master, width='600', height='800')
        canvas.pack()
        canvas.create_rectangle(0, 0, 600, 800, fill='black', outline='black')

        character = canvas.create_rectangle(270, 730, 330, 760, fill='blue', outline='red')
        left = 75
        right = 77

        time.sleep(10)
        while True:
            if ord(getch()) == left:
                canvas.move(character, -5, 0)
                canvas.update()
            elif ord(getch()) == right:
                canvas.move(character, 5, 0)
                canvas.update()


root = Tk()
app = Window(root)
app.mainloop()

As you can see, in the def game(self) function, I created a rectangle as the character. Then I used getch() to compare keyboard inputs; pressing the right/left arrow key will move the character respectively. However, this does not work in the window: my window freezes and it says "not responding". I am forced to close the window, thus I do not know if my code is not working or if my computer sucks. Copy and paste this into your editor and please let me know how I can fix this, if possible.

BTW, when you load the window, click file, then start.

Answer 1

I have modified your code to follow PEP8 a little better and corrected the game() method by removing the sleep() method and adding 2 more methods for controlling left and right movement.

By making sure our Canvas is a class attribute and the character is a class attribute we can interact with them from any method within the class.

I made everything into a class attribute that I thought should probably be one.

Updated to include max left and max right.

import tkinter as tk


class Window(tk.Frame):
    def __init__(self, master=None):
        tk.Frame.__init__(self, master)
        self.master.title('Dodger')
        self.master.geometry('600x800')
        self.master.config(bg='black')
        menu = tk.Menu(self.master) 
        file = tk.Menu(menu)
        file.add_command(label='Exit', command=exit)
        file.add_command(label='Start', command=self.game)
        menu.add_cascade(label='File', menu=file)
        self.master.config(menu=menu)

        self.canvas = None
        self.character = None
        self.master.bind("<Left>", self.left_key)
        self.master.bind("<Right>", self.right_key)

    def game(self):
        self.canvas = tk.Canvas(self.master, width='600', height='800')
        self.canvas.pack()
        self.canvas.create_rectangle(0, 0, 600, 800, fill='black', outline='black')
        self.character = self.canvas.create_rectangle(270, 730, 330, 760, fill='blue', outline='red')

    def left_key(self, event):
        cords = self.canvas.coords(self.character)
        if cords[0] <= 5:
            print("Max left")
        else:
            self.canvas.move(self.character, -5, 0)

    def right_key(self, event):  
        cords = self.canvas.coords(self.character)
        if cords[2] >= 595:
            print("Max Right")
        else:
            self.canvas.move(self.character, 5, 0)


root = tk.Tk()
app = Window(root).pack(fill="both", expand=1)
root.mainloop()