C++ Snake pop（）：它消失了

因为我的上一个主题充满了编辑过的版本，一点也不清楚，因为我改变了很多东西，现在我明白了如何做到这一点，所以我要问一个关于我的蛇的新问题：为什么我的蛇消失了，因为当我调用advanceStep时，是的，它弹出一个元素，但就在它推回另一个元素之后？ 谢谢你的帮助，我会有更好的态度。通过@Jason C，要求某人放弃，或者对他说我偷了别人的代码，或者说这是一个家庭作业，也应该得到更好的态度。 提前谢谢

#include <SFML/Window.hpp>
#include <SFML/Graphics.hpp>
#include <SFML/System.hpp>
#include <SFML/Audio.hpp>
#include <deque>

void advanceStep();

sf::Event event;
/*sf::Clock clockSnake;
sf::Time elapse;*/

sf::Vector2i direction(0, 0);


class SnakeBlock
{
public:

sf::Texture texture;
sf::Sprite snakeblock;
int dir;
int lastX, lastY;
};

std::deque<SnakeBlock> Snake;

int main()
{
//elapse = clockSnake.getElapsedTime();

sf::Music epicMusic;
epicMusic.openFromFile("epicmusic.wav");
epicMusic.play();

SnakeBlock snakeHead;
snakeHead.texture.loadFromFile("spritesheetsnake.png", sf::IntRect(0,0,20,22));
snakeHead.snakeblock.setTexture(snakeHead.texture);
SnakeBlock snakeBody1;
snakeBody1.snakeblock.setTexture(*(snakeHead.snakeblock.getTexture()));
SnakeBlock snakeBody2;
snakeBody2.snakeblock.setTexture(*(snakeHead.snakeblock.getTexture()));

Snake.push_back(snakeHead);
Snake.push_back(snakeBody1);
Snake.push_back(snakeBody2);

Snake[2].snakeblock.setPosition(500,350);
Snake[1].snakeblock.setPosition(475, 338);
Snake[0].snakeblock.setPosition(450, 316);

sf::RenderWindow window(sf::VideoMode(1028,768), "SFML Snake");
window.setFramerateLimit(20);
while(window.isOpen())
{
    while(window.pollEvent(event))
    {
        switch(event.type)
        {
            case sf::Event::Closed:
            epicMusic.stop();
            window.close();
            break;

            default:
            break;
        }

    }

    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left))
    {
            direction.x = -1;
            advanceStep();
            for(int i = 1; i < Snake.size(); i++)
            {
                Snake[i].snakeblock.setPosition(Snake[i+1].snakeblock.getPosition().x-20, Snake[i+1].snakeblock.getPosition().y);
            }
    }
    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right))
    {
            direction.x = 1;
            advanceStep();
            for(int j = 1; j < Snake.size(); j++)
            {
                Snake[j].snakeblock.setPosition(Snake[j+1].snakeblock.getPosition().x+20, Snake[j+1].snakeblock.getPosition().y);
            }
    }
    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Down))
    {
            direction.y = -1;
            advanceStep();
            for(int l = 1; l < Snake.size(); l++)
            {
                Snake[l].snakeblock.setPosition(Snake[l+1].snakeblock.getPosition().x, Snake[l+1].snakeblock.getPosition().y-22);
            }
    }
    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Up))
    {
            direction.y = 1;
            advanceStep();
            for(int o = 1; o < Snake.size(); o++)
            {
                Snake[o].snakeblock.setPosition(Snake[o+1].snakeblock.getPosition().x, Snake[o+1].snakeblock.getPosition().y+22);
            }
    }
    window.clear(sf::Color::Red);
    for(unsigned int m = 0; m < Snake.size(); m++)
    {
        window.draw(Snake[m].snakeblock);
    }
    window.display();
}
return 0;

}

void advanceStep()
{
sf::Vector2f headpos;
headpos.x = Snake[0].snakeblock.getPosition().x;
headpos.y = Snake[0].snakeblock.getPosition().y;

headpos.x += 22 * direction.x;
headpos.y += 22 * direction.y;

SnakeBlock element;
element.snakeblock.setPosition(headpos);

Snake.push_front(element);
Snake.pop_back();
}

---

看起来您正在访问Snake out bounds：

        for(int i = 1; i < Snake.size(); i++)
        {
            ...setPosition(Snake[i+1]....

---

你忘了格式化你的代码。看，这类问题需要花太多时间去挖掘别人的代码；实际上，你需要在逻辑上发现与C++无关的错误，为什么你的实际绘制的for循环从1开始而不是0？对于无符号整数m=1；m<1.5；m++没什么大不了的，说真的，另一方面，人们帮了我很多博士洛夫，谢谢，我刚发完帖子就看到了这一点，所以在你发帖子之前我编辑了它：pThanks，固定大小为大小减1，通过问题更多地位于advanceStep函数中的pop，正如我所说的，因为蛇仍然会消失