Question

我是pygame的新手，一直在尝试创建带有一些按钮的简单界面。当鼠标悬停在按钮上时，我无法更改颜色。

我设法创建了按钮，但无法使其与鼠标交互。该代码使用一个绿色按钮实例创建一个按钮对象。鼠标悬停时，应将按钮从绿色更改为红色。

const db = require('./config/db');
const dbManual = require('./config/dbManual');

(async () => {
    try {
        await db.authenticate();
        console.log('database connected with "sequelize" package');
    } catch (err) {
        console.error(err);
        process.exit(1);
    }
})();

(() => {
    dbManual.connect(err =>
        err
            ? console.error(err)
            : console.log('database connected with "mysql" package')
    );
})();

Answer 1

您的主要问题是您的事件循环中有一个嵌套的事件循环：

while run:         # outer loop
    redrawWindow()
    pygame.display.update()

    for event in pygame.event.get():
        pos = pygame.mouse.get_pos()

        Exit = False
        while not Exit:       # inner loop
            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    print(event)
                    pygame.quit()
                    quit()

当执行到达此内部循环时，不会再次调用redrawWindow()或GrnBut.MouseOver(pos)。

摆脱它：

while run:
    redrawWindow()
    pygame.display.update()

    for event in pygame.event.get():
        pos = pygame.mouse.get_pos()

        if event.type == pygame.QUIT:
            print(event)
            pygame.quit()
            quit()

可以使用pygame的某些功能（例如Sprite和Rect类来改进您的代码。

下面是一个示例，您可以如何创建支持多个不同按钮的Button类的更“ pygamy”版本：

import pygame

pygame.init()

display_width = 1200
display_height = 600

# use python style variable names (lowercase)
screen = pygame.display.set_mode((display_width, display_height))
pygame.display.set_caption('Log In')
clock = pygame.time.Clock()

# load the font only once instead of every frame
font = pygame.font.SysFont('comicsans', 20)

# class name should be singular
class Button(pygame.sprite.Sprite):
    # 1) no need to have 4 parameters for position and size, use pygame.Rect instead
    # 2) let the Button itself handle which color it is
    # 3) give a callback function to the button so it can handle the click itself 
    def __init__(self, color, color_hover, rect, callback, text='', outline=None):
        super().__init__()
        self.text = text
        # a temporary Rect to store the size of the button
        tmp_rect = pygame.Rect(0, 0, *rect.size)

        # create two Surfaces here, one the normal state, and one for the hovering state
        # we create the Surfaces here once, so we can simple blit them and dont have
        # to render the text and outline again every frame
        self.org = self._create_image(color, outline, text, tmp_rect)
        self.hov = self._create_image(color_hover, outline, text, tmp_rect)

        # in Sprites, the image attribute holds the Surface to be displayed...
        self.image = self.org
        # ...and the rect holds the Rect that defines it position
        self.rect = rect
        self.callback = callback

    def _create_image(self, color, outline, text, rect):
        # function to create the actual surface
        # see how we can make use of Rect's virtual attributes like 'size'
        img = pygame.Surface(rect.size)
        if outline:
            # here we can make good use of Rect's functions again
            # first, fill the Surface in the outline color
            # then fill a rectangular area in the actual color
            # 'inflate' is used to 'shrink' the rect
            img.fill(outline)
            img.fill(color, rect.inflate(-4, -4))
        else:
            img.fill(color)

        # render the text once here instead of every frame
        if text != '':
            text_surf = font.render(text, 1, pygame.Color('black'))
            # again, see how easy it is to center stuff using Rect's attributes like 'center'
            text_rect = text_surf.get_rect(center=rect.center)
            img.blit(text_surf, text_rect)
        return img

    def update(self, events):
        # here we handle all the logic of the Button
        pos = pygame.mouse.get_pos()
        hit = self.rect.collidepoint(pos)
        # if the mouse in inside the Rect (again, see how the Rect class
        # does all the calculation for use), use the 'hov' image instead of 'org'
        self.image = self.hov if hit else self.org
        for event in events:
            # the Button checks for events itself.
            # if this Button is clicked, it runs the callback function
            if event.type == pygame.MOUSEBUTTONDOWN and hit:
                self.callback(self)

run = True

# we store all Sprites in a Group, so we can easily
# call the 'update' and 'draw' functions of the Buttons
# in the main loop
sprites = pygame.sprite.Group()
sprites.add(Button(pygame.Color('green'), 
                   pygame.Color('red'), 
                   pygame.Rect(150, 200, 90, 100), 
                   lambda b: print(f"Button '{b.text}' was clicked"),
                   'Press',
                   pygame.Color('black')))

sprites.add(Button(pygame.Color('dodgerblue'), 
                   pygame.Color('lightgreen'), 
                   pygame.Rect(300, 200, 90, 100), 
                   lambda b: print(f"Click me again!"),
                   'Another'))

while run:
    events = pygame.event.get()
    for event in events:
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()

    # update all sprites
    # it now doesn't matter if we have one or 200 Buttons
    sprites.update(events)
    # clear the screen
    screen.fill(pygame.Color('white'))
    # draw all sprites/Buttons
    sprites.draw(screen)
    pygame.display.update()
    # limit framerate to 60 FPS
    clock.tick(60)

Answer 2

您的代码有很多问题，并且希望提出一种不太冗长的方法来使用HashSet而不是pygame.Rect进行编码，因为它不需要过多地了解游戏设计这是一种无继承的方法。

首先我们创建按钮类：

pygame.Sprite

然后我们编写主程序循环（从上一个代码块继续）

import pygame
import sys

class Button:
    def __init__(self, rect, default_colour=(0,255,0), hovered_colour=(255,0,0), text="", font=None): #using default arguments
        self.rect = pygame.Rect(rect)

        self.default_colour = default_colour
        self.hovered_colour = hovered_colour

        self.font = font if font else pygame.font.Font(None, 20) #initialise/import font
        self.text = self.font.render(text, True, (0,0,0)) #render text

    def draw(self, surf, mouse_coords):
        if self.hover(mouse_coords):
            pygame.draw.rect(surf, self.hovered_colour, self.rect, 0)
        else:
            pygame.draw.rect(surf, self.default_colour, self.rect, 0)

        surf.blit(self.text, self.text.get_rect(center=self.rect.center)) #rect has a centre attribute

    def hover(self, mouse):
        mouse_rect = pygame.Rect(mouse, [1,1]) #using inbuilt collision function
        return mouse_rect.colliderect(self.rect) #returns a boolean, no need to do this: if mouse_rect.colliderect(self.rect): return True, else: return False

当我将鼠标悬停在pygame上时，为什么我的按钮不会更改颜色？

2 个答案: