Python Pygame 如何将矩形放在屏幕中央

我真的是新来学习Python和做练习 我想创建一个矩形或任何其他图形，例如我使用的pygame.Rect(x,y,w,h)并设置 screen_center

self.screen_rect=setting.screen.get_rect()
self.screent_center=self.screen_rect.center

但矩形的中心不在屏幕的中心 我也想用self.b=self.bullet.get_rect()但它显示错误 我该如何修复它？ 这是代码：

#! /usr/bin/python
import pygame as p
import sys

class Setting():
    def __init__(self,width,height):
        self.w=width
        self.h=height
        self.flag=p.RESIZABLE
        self.color=(255,255,255)
        self.speed=1
        self.screen=p.display.set_mode((self.w,self.h),self.flag)
        p.display.set_caption("Bullet")
        self.bullet_s=1
        self.bullet_w=100
        self.bullet_h=300
        self.bullet_c=(0,0,0)

class Bullet(p.sprite.Sprite):
    def __init__(self,setting):
        super().__init__()
        self.screen_rect=setting.screen.get_rect()
        self.screent_center=self.screen_rect.center

        self.bullet=p.Rect((self.screen_center),(setting.bullet_w,setting.bullet_h))   **<-- not in the center**


    self.b=self.bullet.get_rect() **<-- AttributeError: 'pygame.Rect' object has no attribute 'get_rect'**
        self.color=setting.bullet_c
        self.speed=setting.bullet_s
#        self.centery=float(self.bullet.centery)
    def bullet_move(self):
        self.y -= self.speed
        self.bullet.y=self.y
    def draw_bullet(self,setting):
        self.rect=p.draw.rect(setting.screen,self.color,self.bullet)


def game():
    p.init()
    setting=Setting(1200,800)
    bullet=Bullet(setting)


    while True:
        for event in p.event.get():
             if event.type == p.QUIT:
                 sys.exit()
        setting.screen.fill((255,0,0))
        bullet.draw_bullet(setting)
        p.display.flip()
game()

此代码使用屏幕上的中心矩形

 self.screen_rect = setting.screen.get_rect()

 self.rect.center = self.screen_rect.center

当您按下时它也会移动矩形UP or DOWN.

It uses KEYDOWN, KEYUP改变speed它运行move()在每个循环中，该函数使用speed改变位置（不检查按键）。

也比较rect.top with screen.top and rect.bottom with screen.bottom当矩形触及屏幕边框时停止矩形。

顺便说一句：我还在代码中添加空格和空行以使其更具可读性。

See: PEP 8——Python 代码风格指南 https://www.python.org/dev/peps/pep-0008/

import pygame as p

class Setting():

    def __init__(self, width, height):
        self.w = width
        self.h = height
        self.flag = p.RESIZABLE
        self.color = (255, 255, 255)
        self.speed = 1

        self.screen = p.display.set_mode((self.w, self.h), self.flag)

        p.display.set_caption("Bullet")

        self.bullet_s = 1
        self.bullet_w = 100
        self.bullet_h = 300
        self.bullet_c = (0, 0, 0)


class Bullet(p.sprite.Sprite):

    def __init__(self, setting):
        super().__init__()

        self.setting = setting

        self.screen_rect = setting.screen.get_rect()

        self.rect = p.Rect(0, 0, setting.bullet_w, setting.bullet_h)
        self.rect.center = self.screen_rect.center

        self.color = setting.bullet_c
        self.speed = 0 #setting.bullet_s

    def move(self):
        self.rect.y -= self.speed

        if self.rect.top < 0:
            self.rect.top = 0
        elif self.rect.bottom > self.screen_rect.bottom:
            self.rect.bottom = self.screen_rect.bottom

    def draw(self):
        p.draw.rect(self.setting.screen, self.color, self.rect)

    def handle_event(self, event):
        if event.type == p.KEYDOWN:

            if event.key == p.K_UP:
                self.speed = self.setting.bullet_s
            elif event.key == p.K_DOWN:
                self.speed = -self.setting.bullet_s

        elif event.type == p.KEYUP:

            if event.key == p.K_UP:
                self.speed = 0
            elif event.key == p.K_DOWN:
                self.speed = 0

def game():
    p.init()
    setting = Setting(1200,800)
    bullet = Bullet(setting)

    running = True
    while running:
        for event in p.event.get():
             if event.type == p.QUIT:
                 running = False
             bullet.handle_event(event)

        bullet.move()

        setting.screen.fill((255, 0, 0))
        bullet.draw()
        p.display.flip()

    p.quit()


game()