我在SFML sf :: RenderWindow中只有黑屏

Question

我尝试在C ++ Windows窗体项目（在这里也是新的：D）中使用SFML的优点（在这里我还是很新的）。 我的想法是，当事件发生时，此SFML窗口弹出以显示图像。 我设法使SFML窗口在事件发生时弹出，但是它仅出现在空白屏幕上，但没有显示我想要的纹理。这是涉及SFML的代码摘录，带有“ //”。 。”我将剪切不必要的代码：

BatteryAlarmDlg.h

class CBatteryAlarmDlg : public CDialog
{
    // ... 
    protected:
    // ...

    // timers
    Timer m_tPowerCheck; // the struct Timer has just two members - int id and int duration
    Timer m_tWindowRefresh;

    // sounds
    sf::SoundBuffer m_sfsbWarningMessageBuffer;
    sf::Sound m_sfsWarningMessageSound;
    std::string m_sPathToWarningMessageSoundFile;

    // sfml window management support
    sf::RenderWindow m_sfwChangePowerMessage;
    sf::Texture m_sftChangePowerMessage;
    sf::RectangleShape m_sfrChangePowerMessage;
    bool m_bIsWindowAlive;
    sf::Event m_sfeEvent;

    // ...
};

在上面的代码中，我只声明成员。

BatteryAlarmDlg.cpp

// ...
BOOL CBatteryAlarmDlg::OnInitDialog()
{
    // ...
    /// init timers ///
    m_tPowerCheck = Timer(42, 1000); // a timer with id == 42 and with a duration == 1,000 ms
    SetTimer(m_tPowerCheck.id, m_tPowerCheck.duration, nullptr);
    m_tWindowRefresh = Timer(1, 15);
    SetTimer(m_tWindowRefresh.id, m_tWindowRefresh.duration, nullptr);

    /// init sounds ///
    m_sPathToWarningMessageSoundFile = "warning-message-2.wav";
    if (!m_sfsbWarningMessageBuffer.loadFromFile(m_sPathToWarningMessageSoundFile))
    {
        MessageBox("Error loading of warning message sound file!");
    }
    m_sfsWarningMessageSound.setBuffer(m_sfsbWarningMessageBuffer);

    /// init messages windows ///
    m_sfwChangePowerMessage.setFramerateLimit(60);
    if (!m_sftChangePowerMessage.loadFromFile("ChagePowerMessage.png"))
    {
        MessageBox("Error loading of warning message image file!");
    }
    m_sfrChangePowerMessage.setSize
        (
            sf::Vector2f(m_sfwChangePowerMessage.getSize().x, m_sfwChangePowerMessage.getSize().y)
        );

    m_sfrChangePowerMessage.setPosition(0, 0);
    m_sfrChangePowerMessage.setTexture(&m_sftChangePowerMessage);
    m_bIsWindowAlive = false;

    return TRUE;  // return TRUE  unless you set the focus to a control
}
    // ...
void CBatteryAlarmDlg::OnTimer(UINT_PTR nIDEvent)
{
    if (nIDEvent == m_tPowerCheck.id)
    {

        if (GetSystemPowerStatus(&m_spsPower) == 0)
        {
            // message = "Error: Could not get the system power status!";
            MessageBox("Error: Could not get the system power status!");
        }       
        if (m_spsPower.ACLineStatus == 0 & m_iPowerChange == 1)
        {
            if (!m_sfwChangePowerMessage.isOpen())
            {
                m_sfwChangePowerMessage.create(sf::VideoMode(800, 600), "Battery allarm : System Power Changed!");
            }
            m_sfwChangePowerMessage.clear();
            m_sfwChangePowerMessage.draw(m_sfrChangePowerMessage);
            m_sfwChangePowerMessage.display();
            m_iPowerChange = 0;
            m_sfsWarningMessageSound.play();
            m_bIsWindowAlive = true;
        }

        if (m_spsPower.ACLineStatus == 1 & m_iPowerChange == 0)
        {
            m_iPowerChange = 1;
        }

    }


    if (nIDEvent = m_tWindowRefresh.id)
    {
        if (m_bIsWindowAlive)
        {
            while (m_sfwChangePowerMessage.pollEvent(m_sfeEvent))
            {
                if
                    (
                        m_sfeEvent.type == sf::Event::Closed ||
                        (m_sfeEvent.type == sf::Event::KeyPressed && m_sfeEvent.key.code == sf::Keyboard::Escape)
                    )
                {
                    m_bIsWindowAlive = false;
                }
            }

            m_sfwChangePowerMessage.clear();
            m_sfwChangePowerMessage.draw(m_sfrChangePowerMessage);

            m_sfwChangePowerMessage.display();
        }

        if(!m_bIsWindowAlive && m_sfwChangePowerMessage.isOpen())
        {
            m_sfwChangePowerMessage.close();
        }
    }
    CDialog::OnTimer(nIDEvent);
}

背后的基本思想是，如果有一个事件，并且第一个计时器（每1秒钟执行一次m_tPowerCheck），然后显示SFML窗口绘制图像，然后播放声音。 每隔15毫秒（m_tWindowRefresh）检查sfml窗口是否打开并重新绘制图片-在这里我不确定是否有必要，因为这是静止图像，但最初我认为黑屏是因为我不刷新它不断。 但仍然-只有黑屏...：\\

编辑：SFML的声音工作正常。

Answer 1

看起来您将sf::RectangleShape m_sfrChangePowerMessage大小设置为sf::Vector2f(0,0) 。 发生这种情况是因为您致电：

m_sfrChangePowerMessage.setSize
        (
            sf::Vector2f(m_sfwChangePowerMessage.getSize().x, m_sfwChangePowerMessage.getSize().y)
        );

在创建窗口之前：

m_sfwChangePowerMessage.create(sf::VideoMode(800, 600), "Battery allarm : System Power Changed!");

我的示例解决方案是替换

m_sfrChangePowerMessage.setSize
        (
            sf::Vector2f(m_sfwChangePowerMessage.getSize().x, m_sfwChangePowerMessage.getSize().y)
        );

到m_sfrChangePowerMessage.setSize(sf::Vector2f(800,600));

另外，您可能对Observer Pattern感兴趣，它可能对您的应用程序有帮助。