SFML 事件不显示？

Question

我的 SFML 程序中的事件功能不起作用。 main() 的一般结构如下。我想注册最后按下的键并相应地切换屏幕。我知道下面会要求按键保持按下状态，但即使这样做作为测试也无法正常工作。

我缺少什么语法？我在论坛上看到的教程和示例代码使它看起来像下面一样简单。我见过用在键码上的开关，但这似乎更适合视频游戏中的即时响应。

int main()
{

    srand (time(NULL));

    sf::RenderWindow window(sf::VideoMode(SIZE, SIZE), "Curling Party");

    window.setFramerateLimit(30);

   ...

    while(window.isOpen())
    {

        sf::Event event;

        window.pollEvent(event);

        if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Q)

        {

            window.close();
            break;
        }

        if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::R)

        {


            ...

            window.display();

        }


        if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::B)

        {

            ...

            window.display();

        }

        if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape)
        {
           ...
        }


        window.clear(sf::Color::White);

        window.draw(house[0]);
        window.draw(house[1]);
        window.draw(house[2]);
        window.draw(house[3]);

        window.display();

    }

    return 0;

}

Answer 1

window.pollEvent(event) 应该在 while 循环中，因为 documentation says:

A mistake that people often make is to forget the event loop, simply because they don't yet care about handling events (they use real-time inputs instead). Without an event loop, the window will become unresponsive. It is important to note that the event loop has two roles: in addition to providing events to the user, it gives the window a chance to process its internal events too, which is required so that it can react to move or resize user actions.

应该只在 window 循环结束时调用 window.display()，不需要在按下每个键后显示 window。

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