Question

#Turtle messing around
import turtle
import os


wn = turtle.Screen()
wn.bgcolor("black")

border = turtle.Turtle()
border.speed(0)
border.penup()
border.color("blue")
border.setposition(-200,-200)
border.setheading(90)
border.pensize(3)
border.pendown()
for x in range(4):
border.fd(400)
border.rt(90)
border.penup()
border.fd(300)
border.rt(90)
border.hideturtle()

#Player graphics
player= turtle.Turtle()
player.setposition(0,-150)
player.color("white")
player.left(90)
player.shape("triangle")
player.shapesize(1)
player.speed(0)
player.penup()
turtle.mainloop()

playerspeed = 15


#Player movement
def moveleft():
    x = player.xcor()
    x -= playerspeed
    if x < -280:
        x = -280
        player.setx(x)
def moveright():
    x = player.xcor()
    x += playerspeed
    if x > -280:
        x = 280
        player.setx(x)


wn.listen()
wn.onkeypress(moveleft, "Left")
wn.onkeypress(moveright, "Right")


turtle.mainloop()

我的代码在上面。

每当我运行它时，普通程序就什么都不做（我尝试用wn替换后三个turtle）。

但是当我关闭窗口时，又弹出一个窗口（仅当最后三个是乌龟时），并且出现以下错误：

     ================================
>>> 
Traceback (most recent call last):
  File "REDACTED", line 54, in <module>
    wn.listen()
  File "G:\python\lib\turtle.py", line 1438, in listen
    self._listen()
  File "G:\python\lib\turtle.py", line 710, in _listen
    self.cv.focus_force()
  File "G:\python\lib\turtle.py", line 426, in focus_force
    self._canvas.focus_force()
  File "G:\python\lib\tkinter\__init__.py", line 428, in focus_force
    self.tk.call('focus', '-force', self._w)
_tkinter.TclError: can't invoke "focus" command:  application has been 
destroyed

我不太确定该怎么做，所有这些错误的内容都使我感到困惑，我也不明白，我感谢我能获得的所有帮助，谢谢。

Answer 1

问题出在第34行。当您调用turtle.mainloop()时，程序将进入无限循环；否则，程序将进入无限循环。下面的代码行都不会执行，包括您的事件监听器。

# ... unchanged code ...

player.speed(0)
player.penup()
turtle.mainloop()  # <--- infinite loop! remove this line.

# code below this line is not executed
playerspeed = 15

# ... unchanged code ...

删除此行，您将看到处理程序触发（如果不确定，请添加调试打印）。最后一行的第二个turtle.mainloop()调用将正确运行窗口。

Answer 2

让我告诉您您的第一个错误：在第13行，您说for x in range(4): 缩进不适用于此。循环时必须缩进，否则会出现错误。

这是我复制您的代码并删除turtle.mainloop()时所得到的：点击链接即可查看

https://i.stack.imgur.com/dI3Lg.gif

此外，turtle.mainloop()部分除了将其保持在无限循环之外不执行任何操作。

如果绝对要在那里，请将其放在末尾。

乌龟键盘绑定，为什么它们不断崩溃？

2 个答案: