Tkinter接鸡蛋游戏报_tkinter.TclError: invalid command name ".!canvas"求解决

报错根因 #

_tkinter.TclError: invalid command name ".!canvas" 报错是因为游戏结束调用root.destroy()销毁窗口后，你之前注册的create_egg、move_eggs、check_catch三个定时任务仍然会触发执行，此时Canvas组件已经被销毁，调用Canvas相关操作就会抛出异常。

除此之外你的代码还有两处逻辑错误导致游戏无法正常运行：

1. 接蛋器初始坐标笔误：catcher_start_x2 = catcher_start_x = catcher_width 应为 catcher_start_x2 = catcher_start_x + catcher_width，否则接蛋器初始位置错误无法接蛋
2. 接蛋判定逻辑错误：check_catch 函数中的 catcher_y2 - egg_y2 - egg_y2 < 40 多减了一次egg_y2，应为 catcher_y2 - egg_y2 < 40

完整修复代码 #

from itertools import cycle
from random import randrange
from tkinter import Canvas, Tk, messagebox, font

canvas_width = 800
canvas_height = 400

root = Tk()
c = Canvas(root, width = canvas_width, height = canvas_height, background="deep sky blue")
c.create_rectangle(-5, canvas_height - 100, canvas_width + 5, canvas_height + 5, fill = "sea green",  width=0)
c.create_oval(-80, -80, 120, 120, fill="orange", width=0)
c.pack()

color_cycle = cycle(["light blue", "light green", "light pink", "light yellow", "light cyan"])
egg_width = 45
egg_height = 55
egg_score = 10
egg_speed = 500
egg_interval = 4000
difficulty_factor = 0.95

catcher_color = "magenta"
catcher_width = 100
catcher_height = 100
catcher_start_x = canvas_width / 2 - catcher_width / 2
catcher_start_y = canvas_height - catcher_width - 20
# 修复接蛋器初始坐标笔误
catcher_start_x2 = catcher_start_x + catcher_width
catcher_start_y2 = catcher_start_y + catcher_height
catcher = c.create_arc(catcher_start_x, catcher_start_y, catcher_start_x2, catcher_start_y2, start = 200, extent = 140, style = "arc", outline = catcher_color, width = 3)

game_font = font.nametofont("TkFixedFont")
game_font.config(size = 18)
score = 0
score_text = c.create_text(10, 10, anchor="nw" , font=game_font, fill="darkblue", text="Score: " + str(score))

lives_remaining = 1
lives_text = c.create_text(canvas_width - 10, 10, anchor="ne", font = game_font, fill="darkblue", text = "Lives: " + str(lives_remaining))

eggs = []
# 新增游戏运行状态标记，避免销毁窗口后定时任务继续执行
game_running = True

def create_egg():
    if not game_running:
        return
    x = randrange(10, 740)
    y = 40
    new_egg = c.create_oval(x, y, x + egg_width, y + egg_height, fill = next(color_cycle), width=0)
    eggs.append(new_egg)
    root.after(egg_interval, create_egg)

def move_eggs():
    if not game_running:
        return
    for egg in eggs:
        (egg_x, egg_y, egg_x2, egg_y2) = c.coords(egg)
        c.move(egg, 0, 10)
        if egg_y2 > canvas_height:
            egg_dropped(egg)
    root.after(egg_speed, move_eggs)

def egg_dropped(egg):
    eggs.remove(egg)
    lose_a_life()
    if lives_remaining == 0:
        global game_running
        # 游戏结束先修改状态标记，停止所有定时任务
        game_running = False
        messagebox.showinfo("Game Over!", "Final Score: " + str(score))
        root.destroy()

def lose_a_life():
    global lives_remaining
    lives_remaining -= 1
    c.itemconfigure(lives_text, text = "Lives: " + str(lives_remaining))

def check_catch():
    if not game_running:
        return
    (catcher_x, catcher_y, catcher_x2, catcher_y2) = c.coords(catcher)
    for egg in eggs:
        (egg_x, egg_y, egg_x2, egg_y2) = c.coords(egg)
        # 修复接蛋判定逻辑错误
        if catcher_x < egg_x and egg_x2 < catcher_x2 and catcher_y2 - egg_y2 < 40:
            eggs.remove(egg)
            c.delete(egg)
            increase_score(egg_score)
    root.after(100, check_catch)
    

def increase_score(points):
    global score, egg_speed, egg_interval
    score += points
    egg_speed = int(egg_speed * difficulty_factor)
    egg_interval = int(egg_interval * difficulty_factor)
    c.itemconfigure(score_text, text="Score: " + str(score))

def move_left(event):
    (x1, y1, x2, y2) = c.coords(catcher)
    if x1 > 0:
        c.move(catcher, -20, 0)

def move_right(event):
    (x1, y1, x2, y2) = c.coords(catcher)
    if x2 < canvas_width:
        c.move(catcher, 20, 0)

c.bind("<Left>" , move_left)
c.bind("<Right>" , move_right)
c.focus_set()

root.after(1000, create_egg)
root.after(1000, move_eggs)
root.after(1000, check_catch)
root.mainloop()

内容的提问来源于stack exchange，提问作者Hallows