将结构的枚举传递给其他函数并分配值

时间:2014-01-21 21:21:55

标签: c++ data-structures enums

我正在用C ++编写一个Snake游戏,我有一个蛇形部分的结构,其中包含x位置,y位置,方向等数据。

我把它全部工作,将所有数据设置为整数,我只是想将一些数据类型更改为枚举,因为它看起来更整洁,更容易理解。 我已经尝试了许多并在线查看,但我似乎找不到任何东西。

这是一些结构:

struct SnakeSection
{
    int snakePosX;
    int snakePosY;

    int SectionType;
    // Tail = 0, Body = 1, Head = 2

    int animation;

  enum Direction
  {
      Up = 0,
      Right = 1,
      Down = 2,
      Left = 3
  };
};

我尝试将其中一个路线传递给另一个功能:

void PlayerSnake::createSnake()
{
// Parameters are direction, x and y pos, the blocks are 32x32
addSection(SnakeSection::Direction::Right, mStartX, mStartY, 2);
}

然后我尝试将方向设置为该函数中传入的方向:

void PlayerSnake::addSection(SnakeSection::Direction dir, int x, int y, int type)
{
    //Create a temp variable of a Snake part structure
    SnakeSection bufferSnake;

    bufferSnake.Direction = dir;
    bufferSnake.animation = 0;

    //is it head tail or what? This is stored in the Snake section struct
    //TODO Add different sprites for each section
    bufferSnake.SectionType = type;

    //assign the x and y position parameters to the snake section struct buffer
    bufferSnake.snakePosX = x;
    bufferSnake.snakePosY = y;

    //Push the new section to the back of the snake.
    lSnake.push_back(bufferSnake);
}

错误:无效使用枚举SnakeSection :: Direction

由于

1 个答案:

答案 0 :(得分:0)

以下行中的错误......

bufferSnake.Direction = dir;

...有理由认为,除了声明enum类型之外,你还需要有一个类成员变量来存储它:

struct SnakeSection
{
    int snakePosX;
    int snakePosY;

    int SectionType;
    // Tail = 0, Body = 1, Head = 2

    int animation;

  enum Direction
  {
      Up = 0,
      Right = 1,
      Down = 2,
      Left = 3
  };

  Direction direction_; // <<<<<<<<<<<<<< THAT'S WHAT'S MISSING IN YOUR CODE
};

参考

bufferSnake.direction_= dir; // <<<<<<<<<<<<<< THAT'S THE MEMBER VARIABLE YOU'LL 
                             //                HAVE TO REFER TO!