QT、C++實作的貪吃蛇小游戲

鍵盤方向鍵控制蛇移動，隨機生成身體顏色，食物會閃爍

蛇身及食物的一些屬性：

// 坐標屬性
struct point
{
    int x;
    int y;
};

// 蛇的屬性
struct Snake
{
    vector <point> xy;			// 每節坐標
    point next;					// 為下一節預留的位置
    vector <QColor> color;      // 每節顏色
    int num;					// 長度
    int position;				// 方向
};

// 食物的屬性
struct Food
{
    point fdxy[10];			// 坐標
    int grade;				// 分數
    int num = 1;			// 食物總數
    QColor color[10];		// 食物顏色
};

enum position { Up, Down, Left, Right,None };		// 列舉蛇的方向

初始化蛇：

void Widget::initSnake()
{
    point xy;
    xy.x = 20;
    xy.y = 0;
    snake.xy.push_back(xy);
    snake.color.push_back(QColor(rand() % 256, rand() % 256, rand() % 256));	// 設定一個隨機顏色
    xy.x = 10;
    xy.y = 0;
    snake.xy.push_back(xy);
    snake.color.push_back(QColor(rand() % 256, rand() % 256, rand() % 256));	// 設定一個隨機顏色
    xy.x = 0;
    xy.y = 0;
    snake.xy.push_back(xy);
    snake.color.push_back(QColor(rand() % 256, rand() % 256, rand() % 256));	// 設定一個隨機顏色
    snake.num = 3;
    snake.position = None;

    timer=new QTimer(this);
    timer->start(1);
    connect(timer,SIGNAL(timeout()),SLOT(Snake_update()));//每1時間觸發一次Snake_update()函式
}

控制蛇的移動：

void Widget::moveSnake()
{
    // 將預留節設定為未移動前的尾節
    snake.next = snake.xy[snake.num - 1];
    // 將除蛇頭以外的節移動到它的前面一節
    for (int i = snake.num - 1; i >= 1; i--)
        snake.xy[i] = snake.xy[i - 1];
    // 根據當前移動方向移動蛇頭
    switch (snake.position)
    {
    case Right:
        snake.xy[0].x += 10;
        break;
    case Left:
        snake.xy[0].x -= 10;
        break;
    case Up:
        snake.xy[0].y -= 10;
        break;
    case Down:
        snake.xy[0].y += 10;
    }
}

初始化食物：

void Widget::initFood(int num)
{
    food.fdxy[num].x = rand() % 80 * 10;
    food.fdxy[num].y = rand() % 60 * 10;
    for (int i = 0; i < snake.num; i++)
        if (food.fdxy[num].x == snake.xy[i].x && food.fdxy[num].y == snake.xy[i].y)		// 避免食物生成在蛇身上
        {
            food.fdxy[num].x = rand() % 80 * 10;
            food.fdxy[num].y = rand() % 60 * 10;
        }
}

蛇吃食物：

void Widget::eatFood()
{
    for (int i = 0; i <= food.num - 1; i++)
        if (snake.xy[0].x == food.fdxy[i].x && snake.xy[0].y == food.fdxy[i].y)
        {
            snake.num++;
            snake.xy.push_back(snake.next);					// 新增一個節到預留位置
            snake.color.push_back(food.color[i]);			// 將新增節的顏色設定為當前吃掉食物的顏色
            food.grade += 100;
            initFood(i);
            if (food.num < 10 && food.grade % 500 == 0 && food.grade != 0)
            {
                food.num++;									// 每得 500 分，增加一個食物，但食物總數不超過 10 個
                initFood(food.num - 1);						// 初始化新增加的食物
            }
            break;
        }
}

重繪畫面：

void Widget::Snake_update()
{
    Sleep(150);
    moveSnake();
    eatFood();
    drawFood();
    drawSnake();
    showgrade();
    update();//呼叫paintEvent函式
}

游戲結束條件：

bool Widget::gameOver()
{
    // 撞墻，將墻向外擴展一圈（否則蛇無法到達地圖邊緣）
    if (snake.xy[0].y <= 0 && snake.position == Up)			return true;
    if (snake.xy[0].y >= 600 && snake.position == Down)	return true;
    if (snake.xy[0].x <= 0 && snake.position == Left)			return true;
    if (snake.xy[0].x >= 800 && snake.position == Right)	return true;
    // 撞自己
    for (int i = 1; i < snake.num; i++)
    {
        if (snake.xy[0].x <= snake.xy[i].x + 10 && snake.xy[0].x >= snake.xy[i].x && snake.xy[0].y == snake.xy[i].y && snake.position == Left)
            return true;
        if (snake.xy[0].x + 10 >= snake.xy[i].x && snake.xy[0].x + 10 <= snake.xy[i].x + 10 && snake.xy[0].y == snake.xy[i].y && snake.position == Right)
            return true;
        if (snake.xy[0].y <= snake.xy[i].y + 10 && snake.xy[0].y >= snake.xy[i].y && snake.xy[0].x == snake.xy[i].x && snake.position == Up)
            return true;
        if (snake.xy[0].y + 10 >= snake.xy[i].y && snake.xy[0].y + 10 <= snake.xy[i].y + 10 && snake.xy[0].x == snake.xy[i].x && snake.position == Down)
            return true;
    }
    return false;
}

鍵盤監聽事件：

void Widget::keyPressEvent(QKeyEvent *event)
{
    switch(event->key())
    {
    case Qt::Key_Up:
        if (snake.position != Down)
        {
            snake.position = Up;
        }
        break;
    case Qt::Key_Down:
        if (snake.position != Up)
        {
            snake.position = Down;
        }
        break;
    case Qt::Key_Right:
        if (snake.position != Left)
        {
            snake.position = Right;
        }
        break;
    case Qt::Key_Left:
        if (snake.position != Right)
        {
            snake.position = Left;
        }
        break;
    default: ;
    }
}

paintEvent：

void Widget::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    QPen pen;
    QBrush brush;
    QFont font("方正舒體",12,QFont::ExtraLight,false);

    painter.setRenderHint(QPainter::Antialiasing);

        pen.setColor(Qt::black);
        //brush.setColor(Qt::green);
        brush.setStyle(Qt::SolidPattern);
        painter.setPen(pen);
        painter.setBrush(brush);

    //畫蛇
    if(snakeTag==1)
    {
        for (int i = 0; i < snake.num; i++)
        {
            brush.setColor(snake.color[i]);
            painter.setPen(pen);
            painter.setBrush(brush);
            painter.drawRect(snake.xy[i].x, snake.xy[i].y, 10, 10);
        }
        snakeTag=0;
    }
    //畫食物
    if(foodTag==1)
    {
        for (int i = 0; i <= food.num - 1; i++)
        {
            brush.setColor(food.color[i] = QColor(rand() % 256, rand() % 256, rand() % 256));
            painter.setPen(pen);
            painter.setBrush(brush);
            painter.drawRect(food.fdxy[i].x, food.fdxy[i].y,10,10);
        }
        foodTag=0;
    }
    //顯示分數
    if(gradeTag==1)
    {
        pen.setColor(QColor(147, 112, 219));
        painter.setPen(pen);
        painter.setFont(font);
        painter.drawText(20,20,QString("當前得分：")+QString("%1").arg(food.grade));
        gradeTag=0;
    }
    if(gameOver())
    {
        timer->stop();
        overTag=1;
        pen.setColor(QColor(147, 112, 219));
        painter.setPen(pen);
        painter.setFont(font);
        painter.drawText(20,40,QString("Game over!"));
    }
}

源代碼（點這里）QwQ