成员未声明范围?

| 因此,在完成一本入门书籍之后,我正在尝试一些C ++,但是我陷入了困境。我已经制作了一个对象向量,每个对象都有一个SFML圆对象作为成员,我希望main()去绘制这些圆。该向量称为
theBoard
,但是当我尝试访问它时,出现以下错误消息:
error: request for member \'theBoard\' in \'GameBoard\', which is of non-class type \'Board*\'
error: \'theBoard\' was not declared in this scope
我是新手(来自Python两年),所以我确定自己在某个地方犯了错误。这是创建董事会的相关代码:
class Board
{
public:
    //These are the member functions.
    Board();
    ~Board();
    vector<Space*> CreateBoard();
    //This will be the game board.
    vector<Space*> theBoard;
    //These clusters represent the waiting areas for pieces not yet in the game.
    vector<Space*> Cluster1;
    vector<Space*> Cluster2;
    vector<Space*> Cluster3;
private:
    //These integers represent the number of spaces on each row, starting at the top     (which is row [0])
    vector<int> RowNums;
};

Board::Board()
{
    //Fill in RowNums with the right values.
    RowNums.push_back(1);
    RowNums.push_back(17);
    RowNums.push_back(2);
    RowNums.push_back(17);
    RowNums.push_back(1);
    RowNums.push_back(1);
    RowNums.push_back(5);
    RowNums.push_back(2);
    RowNums.push_back(7);
    RowNums.push_back(2);
    RowNums.push_back(11);
    RowNums.push_back(3);
    RowNums.push_back(17);
    RowNums.push_back(4);
    RowNums.push_back(17);
    //Then, create the board.
    theBoard = CreateBoard();
}
CreateBoard()是一个非常长的函数,它返回指向Space对象的指针向量。我怀疑这里是否存在问题,因为当我尝试访问main()中的Space对象的圆成员时,我收到的唯一错误消息是。在我看来,我好像已经在相关范围内声明了“ 0”,即,作为Board类的数据成员。 我的main()函数很重要:
int main()
{
    //This sets up the display window.
    sf::RenderWindow App(sf::VideoMode(1200, 900, 32), \"Malefiz\");

    //This creates the board on the heap, and a pointer to it.
    Board* GameBoard = new Board();

    cout << \"Board made.\";

    //This is the game loop.
    while(App.IsOpened())
    {
        //This is used to poll events.
        sf::Event Event;
        while(App.GetEvent(Event))
        {
            //This closes the window.
            if(Event.Type == sf::Event::Closed)
            {
                App.Close();
            }
        }

        //This gets the time since the last frame.
        //float ElapsedTime = App.GetFrameTime();

        //This fills the window with black.
        App.Clear(sf::Color(200, 200, 125));
        //This draws the places into the window.
        for(int i = 0; i < GameBoard.theBoard.size(); ++i)
        {
            App.Draw(GameBoard.*theBoard[i].m_Circle);
        }
        //This displays the window.
        App.Display();
    }

    return EXIT_SUCCESS;
}
    
已邀请:
        如果仔细阅读,该错误将非常明显:
error: request for member \'theBoard\' in \'GameBoard\', which is of non-class type \'Board*\'
error: \'theBoard\' was not declared in this scope
第一行告诉您,您有一个指向
Board
对象的指针,并且您正在尝试直接访问成员。那是:
Board *p = ...
p.theBoard;     // Error, should be p->theBoard, as p is a pointer
另请注意,
GameBoard.*theBoard[i].m_Circle
可能不是您想要的,您可能想要want9 am之类的东西(我想是因为缺少一些重要的位)。     
        在
main()
函数中,
GameBoard
Board *
,而不是
Board
。因此,要访问成员,您需要使用
->
而不是
.
。例如。:
GameBoard->theBoard.size()
[某些人(我是其中的一个)喜欢用前缀
p
ptr
命名它们的指针变量,以便清楚地表明这种刺激。]     
        GameBoard是指向Board对象的指针,因此您需要使用\“-> \”运算符而不是\“。\”运算符来访问其任何成员变量或方法。     
        
GameBoard
是一个指针,因此语法应为:
 for(int i = 0; i < GameBoard->theBoard.size(); ++i)
 {
        App.Draw((GameBoard->theBoard[i])->m_Circle);
 }
由于
theBoard
的元素也是指针,因此在访问
m_Circle
时我使用了指针符号。     

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