Pygame如何绘制一个小人在窗口内移动

利用·pygame.draw模块可以绘制一些简单的图像，但是这只是一些静态图像。只有可以对这些图像进行操作才会产生游戏性，我们怎样可以实现利用键盘控制图像使它移动呢？

函数实现

首先，图像的移动本质其实就是点的移动。可以根据一个参考点绘制出相对应的图像，改变参考点的坐标就可以实现图像的整体移动。

# 传入左上角的位置坐标
BLACK = (0, 0, 0)
def drawMan(left, top):pygame.draw.circle(screen, BLACK, (left+50, top+30), 30, 2)pygame.draw.line(screen, BLACK, (left+50, top+60), (left+50, yop+140), 2)pygame.draw.line(screen, BLACK, (left+50, top+140), (left, top+200), 2)pygame.draw.line(screen, BLACK, (left+50, top+140), (left+100, top+200), 2)pygame.draw.line(screen, BLACK, (left+50, top+100), (left, top+60), 2)pygame.draw.line(screen, BLACK, (left+50, top+100), (left+100, top+60), 2)

类实现

利用以上函数就可以通过控制左上角的位置坐标来实现小人的移动，但是这样要进行其他的操作就比较困难，那么如果我们可以把这个图像绘制在另外一个Surface对象上，那么就会比较容易一些。这个时候我们就可以使用pygame中的pygame.sprite.Sprite精灵类，精灵可以看作是一个屏幕上的图形对象，并且可以实现移动等一系列操作。如何使用可以参考官方文档：官方文档链接

最简单的一个继承pygame.sprite.Sprite精灵类的实现方法（来源于官方文档）：

class Block(pygame.sprite.Sprite):# Constructor. Pass in the color of the block,# and its x and y positiondef __init__(self, color, width, height):# Call the parent class (Sprite) constructorpygame.sprite.Sprite.__init__(self)# Create an image of the block, and fill it with a color.# This could also be an image loaded from the disk.self.image = pygame.Surface([width, height])self.image.fill(color)# Fetch the rectangle object that has the dimensions of the image# Update the position of this object by setting the values of rect.x and rect.yself.rect = self.image.get_rect()

模仿这样的模式可以将我们需要的类创建出来：

class man(pygame.sprite.Sprite):# 是否在移动的状态moveup = Falsemovedown = Falsemoveleft = Falsemoveright = False# 移动速度movespeed = 5def __init__(self, bgcolor, initial_pos):pygame.sprite.Sprite.__init__(self)self.image = pygame.Surface((100, 200))self.image.fill(bgcolor)pygame.draw.circle(self.image, BLACK, (50, 30), 30, 2)pygame.draw.line(self.image, BLACK, (50, 60), (50, 140), 2)pygame.draw.line(self.image, BLACK, (50, 140), (0, 200), 2)pygame.draw.line(self.image, BLACK, (50, 140), (100, 200), 2)pygame.draw.line(self.image, BLACK, (50, 100), (0, 60), 2)pygame.draw.line(self.image, BLACK, (50, 100), (100, 60), 2)self.rect = self.image.get_rect()self.rect.topleft = initial_pos# 方向和限定区域作为参数是，限定区域是一个四元元组，(left, top, width, height),表示一个矩形区域def canMove(self, direction, bound):if direction == left and self.rect.left - self.movespeed > bound[0]:self.moveleft = Truereturnelif direction == left and self.rect.left - self.movespeed <= bound[0]:self.rect.left = bound[0] # 如果继续移动超过了区域，那么直接移动到边界self.moveleft = Falsereturn if direction == up and self.rect.top > bound[1]:self.moveup = Truereturnelif direction == up and self.rect.top - self.movespeed <= bound[1]:self.rect.top = bound[1]self.moveup = Falsereturn     if direction == down and self.rect.bottom < bound[3]:self.movedown = Truereturnelif direction == down and self.rect.bottom + self.movespeed >= bound[3]:self.rect.bottom = bound[3]self.movedown = Falsereturn if direction == right and self.rect.right < bound[2]:self.moveright = Trueelif direction == right and self.rect.right + self.movespeed >= bound[0]:self.rect.right = bound[2]self.moveright = Falsereturn # 移动函数def Moveleft(self):if self.moveleft:self.rect.left -= self.movespeeddef Moveright(self):if self.moveright:self.rect.right += self.movespeeddef Moveup(self):if self.moveup:self.rect.top -= self.movespeeddef Movedown(self):if self.movedown:self.rect.top += self.movespeed

完整代码：

import pygame, sys
from pygame.locals import *FPS = 60
WINDOWWIDTH = 1000
WINDOWHEIGHT = 800
SIZE = (WINDOWWIDTH, WINDOWHEIGHT)
BOUND = (0, 0, WINDOWWIDTH, WINDOWHEIGHT)
WHITE = (255, 255, 255)
BLACK = (0, 0 ,0)
RED = (255,0,0)left = 'left'
up = 'up'
right = 'right'
down = 'down'class man(pygame.sprite.Sprite):moveup = Falsemovedown = Falsemoveleft = Falsemoveright = Falsemovespeed = 5def __init__(self, bgcolor, initial_pos):pygame.sprite.Sprite.__init__(self)self.image = pygame.Surface((100, 200))self.image.fill(bgcolor)pygame.draw.circle(self.image, BLACK, (50, 30), 30, 2)pygame.draw.line(self.image, BLACK, (50, 60), (50, 140), 2)pygame.draw.line(self.image, BLACK, (50, 140), (0, 200), 2)pygame.draw.line(self.image, BLACK, (50, 140), (100, 200), 2)pygame.draw.line(self.image, BLACK, (50, 100), (0, 60), 2)pygame.draw.line(self.image, BLACK, (50, 100), (100, 60), 2)self.rect = self.image.get_rect()self.rect.topleft = initial_posdef canMove(self, direction, bound):if direction == left and self.rect.left - self.movespeed > bound[0]:self.moveleft = Truereturnelif direction == left and self.rect.left - self.movespeed <= bound[0]:self.rect.left = bound[0]self.moveleft = Falsereturn if direction == up and self.rect.top > bound[1]:self.moveup = Truereturnelif direction == up and self.rect.top - self.movespeed <= bound[1]:self.rect.top = bound[1]self.moveup = Falsereturn     if direction == down and self.rect.bottom < bound[3]:self.movedown = Truereturnelif direction == down and self.rect.bottom + self.movespeed >= bound[3]:self.rect.bottom = bound[3]self.movedown = Falsereturn if direction == right and self.rect.right < bound[2]:self.moveright = Trueelif direction == right and self.rect.right + self.movespeed >= bound[0]:self.rect.right = bound[2]self.moveright = Falsereturn def Moveleft(self):if self.moveleft:self.rect.left -= self.movespeeddef Moveright(self):if self.moveright:self.rect.right += self.movespeeddef Moveup(self):if self.moveup:self.rect.top -= self.movespeeddef Movedown(self):if self.movedown:self.rect.top += self.movespeeddef main():global screenpygame.init()screen = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT))screen.fill(WHITE)FPSCLOCK = pygame.time.Clock()Man = man(WHITE, (50,100))# Man.draw()screen.blit(Man.image, Man.rect)pygame.display.update()while True:checkQuit()# 如果想要长按一直移动，不能根据KEYDOWN事件执行操作，那样按一次按键只能动一次，所以可以使用类中的移动状态for event in pygame.event.get():if event.type == KEYDOWN:if event.key == K_a:Man.canMove(left, BOUND)elif event.key == K_w:Man.canMove(up, BOUND)elif event.key == K_s:Man.canMove(down, BOUND)elif event.key == K_d:Man.canMove(right, BOUND)if event.type == KEYUP:if event.key == K_a:Man.moveleft = Falseelif event.key == K_w:Man.moveup = Falseelif event.key == K_s:Man.movedown = Falseelif event.key == K_d:Man.moveright = Falseif Man.moveleft:Man.canMove(left, BOUND)Man.Moveleft()elif Man.moveright:Man.canMove(right, BOUND)Man.Moveright()if Man.moveup:Man.canMove(up, BOUND)Man.Moveup()elif Man.movedown:Man.canMove(down, BOUND)Man.Movedown()screen.fill(WHITE)screen.blit(Man.image, Man.rect)pygame.display.update()FPSCLOCK.tick(FPS)def terminate():pygame.quit()sys.exit()def checkQuit():for event in pygame.event.get(QUIT):terminate()for event in pygame.event.get(KEYDOWN):if event.key == K_ESCAPE:terminate()pygame.event.post(event)if  __name__ == '__main__':main()

效果：