错误C2280:尝试引用已删除的功能

Question

我是游戏开发的新手,也是c ++的新手,但我已经开始开发一款小型的Arkanoid游戏了.我以前运行它,但在重构(引入ArkanoidGame类)后它没有编译,我无法弄清楚为什么.

我得到的错误是:

d:\dropbox\development\gamedev\c++\arkanoid\arkanoid\main.cpp(14): error C2280:
    'ArkanoidGame::ArkanoidGame(void)' : attempting to reference a deleted function
d:\dropbox\development\gamedev\c++\arkanoid\arkanoid\arkanoidgame.h(25) : 
    compiler has generated 'ArkanoidGame::ArkanoidGame' here

我根本不明白这意味着什么,不知道如何解决它.

我已经包含了有问题的课程:

Main.cpp的:

#include "ArkanoidGame.h"

int main() {
    ArkanoidGame game;
    game.init(800, 600);
    while (game.isRunning()) {
        game.checkInput();
        game.checkCollisions();
        game.draw();
    }
    return 0;
}

Arkanoid.h:

#include "Ball.h"
#include "Pad.h"
#include <SFML/Graphics.hpp>
#include <stdarg.h>
#include <memory>

class ArkanoidGame
{
private:
    bool running;
public:
    void ArkanoidGame::init(int, int);
    bool ArkanoidGame::isRunning();
    void ArkanoidGame::checkCollisions();
    void ArkanoidGame::checkInput();
    void ArkanoidGame::update();
    void ArkanoidGame::draw();
    sf::RenderWindow* window;
    Pad pad;
    Ball ball;
};

ArkanoidGame.cpp:

#include "ArkanoidGame.h"

void ArkanoidGame::init(int windowWidth, int windowHeight) {
    window = new sf::RenderWindow(sf::VideoMode(windowWidth, windowHeight), "Arkanoid!");
    window->setFramerateLimit(60);

    ArkanoidGame::running = true;

    //Init pad
    pad = Pad((float)(windowWidth / 2), (float)(windowHeight - 50));

    //Init ball
    ball = Ball(0.f, 0.f);
}

template<class T1, class T2> bool intersect(T1& mA, T2& mB) {
    return mA.right() >= mB.left() && mA.left() <= mB.right()
        && mA.bottom() >= mB.top() && mA.top() <= mB.bottom();
}

void ArkanoidGame::checkCollisions() {
    if (!intersect(pad, ball)) return;

    ball.velocity.y = -ball.ballVelocity;

    if (ball.x() < pad.x()) {
        ball.velocity.x = -ball.ballVelocity;
    }
    else {
        ball.velocity.x = ball.ballVelocity;
    }
}

void ArkanoidGame::update() {
    //Update positions
    pad.update(window->getSize().x);
    ball.update(window->getSize().x, window->getSize().y);
}

void ArkanoidGame::draw() {
    window->clear(Color::Black);
    window->draw(pad.getShape());
    window->draw(ball.getShape());
    window->display();
}

void ArkanoidGame::checkInput() {
    if (Keyboard::isKeyPressed(Keyboard::Key::Escape)) {
        running = false;
    }
}

bool ArkanoidGame::isRunning() {
    return running;
}

Answer 1

据推测,Pad或者Ball(或两者)都没有默认构造函数; 因此,不能为包含它们的类生成一个.必须使用其声明的构造函数初始化它们.

最好的解决方案是删除你的奇怪init函数,并用构造函数替换它:

ArkanoidGame(int windowWidth, int windowHeight) :
    running(true),
    window(new ...),
    Pad(windowWidth / 2, windowHeight - 50),
    Ball(0,0)
{
    window->setFramerateLimit(60);
}

int main() {
    ArkanoidGame game(800, 600);
    // ...
}

如果你真的想出于某种原因两级初始化舞蹈,那么你就需要为双方提供默认的构造函数Pad和Ball.我不建议这样做; 如果无法在无效状态下创建对象,则可以减少错误的范围.

Answer 2

我认为问题是Pad类或类Ball没有默认构造函数(在ArkanoidGame的类定义中有两个这些类的dtat成员:Pad pad;和Ball ball;).在这种情况下,编译器将类ArkanoidGame的默认构造函数定义为已删除(否则它将是格式错误的).但是在第一线主力

ArkanoidGame game;

您尝试调用类ArkanoidGame的默认构造函数.

还要考虑到成员函数的声明在类定义中应具有不合格的名称.例如这个声明

void ArkanoidGame::init(int, int);

是无效的.应该

void init(int, int);