使键绑定适用于 Space Invaders 游戏

本文介绍了使键绑定适用于 Space Invaders 游戏的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在做一个教程来制作太空入侵者"以学习 Python，但我在绑定我的密钥时遇到了问题.无论我将 move_left 和 move_right 函数改成什么键，飞船都不会移动，也没有错误可以追踪.

I'm doing a tutorial to make "Space Invaders" in order to learn Python but I'm encountering an issue in binding my keys. No matter what keys I change the move_left and move_right functions to, the spaceship doesn't move at all, and there is no error to trace it to either.

我曾尝试查看处理类似问题的论坛和 YouTube，但都没有奏效.

I have tried looking at forums that dealt with a similar issue, and YouTube, but none of them have worked at all.

#Modules import turtle #Screen wn = turtle.Screen() wn.bgcolor("black") wn.title("Space invaders") # Border border_pen = turtle.Turtle() border_pen.speed(0) border_pen.color("white") border_pen.penup() border_pen.setposition(-300, -300) border_pen.pendown() border_pen.pensize(3) for sides in range(4): border_pen.fd(600) border_pen.lt(90) border_pen.hideturtle() # Create the player turtle player = turtle.Turtle() player.color("blue") player.shape("triangle") player.penup() player.speed(0) player.setposition(0, -250) player.setheading(90) playerspeed = 15 # move player left and right def move_left(): x = player.xcor() x -= playerspeed player.setx(x) def move_right(): x = player.xcor() x+=playerspeed player.setx(x) # keyboard bindings wn.onkey(move_left(), "Left") wn.onkey(move_right(),"Right") wn.listen() turtle.mainloop()

当我按下向左"和向右"箭头键时，我希望玩家海龟向左和向右移动.

I expect the player turtle to move left and right when I press the "Left" and "Right" arrow keys.

推荐答案

问题出在这两行代码上:

The problem is with these two lines of code:

wn.onkey(move_left(), "Left") wn.onkey(move_right(),"Right")

你不想调用move_left()，你想传递move_left在按键被按下时被事件处理程序调用:

You don't want to call move_left(), you want to pass move_left to be called by the event handler when the key is pressed:

wn.onkey(move_left, 'Left') wn.onkey(move_right, 'Right')

通过包含括号，您传递了 move_left() 的返回值，即 None，有效地禁用事件而不是启用它！

By including the parentheses, you pass the return value of move_left() which is None, effectively disabling the event instead of enabling it!

这是使用上述修复程序重新编写的代码:

Here's a rework of your code with the above fix:

from turtle import Screen, Turtle screen = Screen() screen.bgcolor('black') screen.title("Space invaders") # Border border_pen = Turtle() border_pen.hideturtle() border_pen.pensize(3) border_pen.speed('fastest') border_pen.color('white') border_pen.penup() border_pen.setposition(-300, -300) border_pen.pendown() for _ in range(4): border_pen.forward(600) border_pen.left(90) # Create the player turtle player = Turtle() player.shape('triangle') player.speed('fastest') player.color('blue') player.penup() player.setposition(0, -250) player.setheading(90) playerspeed = 15 # Move player left and right def move_left(): x = player.xcor() - playerspeed player.setx(x) def move_right(): x = player.xcor() + playerspeed player.setx(x) # Keyboard bindings screen.onkey(move_left, 'Left') screen.onkey(move_right, 'Right') screen.listen() screen.mainloop()