如何向创建对象的类发送消息

Question

我想将数据发回创建此对象的类。

这与游戏有关。敌方对象具有线程功能，并在场景中自行移动。

如果您将创建对象的类中的头文件包含在对象本身中，则会产生很多错误......传递指针。

敌方职业：

Class Enemy
{
   private:
      void (*iChange)(DWORD &);
}:
Enemy::Enemy(void (*iChangeHandler)(DWORD &) ) : iChange(0)
{
    this->iChange = iChangeHandler;
}
    void Enemy::Draw(D3DGraphics& gfx)
{
    this->iChange(this->dwThreadID); // send a message back to the class that created me
    gfx.PutPixel(this->my_position_x + 0,this->my_position_y,this->red,this->blue,this->green);
    this->grafix->DrawCircle(this->my_position_x + 0,this->my_position_y, this->radius, this->red,this->blue,this->green);
    (sprintf)( this->enemy_buffer, "X: %d, Y: %d", this->my_position_x , this->my_position_y);
    this->grafix->DrawString( this->enemy_buffer, this->my_position_x , this->my_position_y, &fixedSys, D3DCOLOR_XRGB(255, 0, 0) );
}

游戏类：

struct enemies_array_ARRAY {
        std::string name;
        DWORD ID;
        Enemy* enemy;
    } enemies_array[25];
void Game::EnemyEvent(DWORD &thread_id)
{   
     enemies_array[0]...... // i want to acces this struct array
}
Game::Game(HWND hWnd)
{
    enemies_array[0].name = "john Doe";
    enemies_array[0].ID = NULL;
    enemies_array[0].enemy =  new Enemy(&Game::EnemyEvent);   
    // error: C2664:
    // another attemp
    enemies_array[0].name = "john Doe";
    enemies_array[0].ID = NULL;
    enemies_array[0].enemy =  new Enemy(Game::EnemyEvent);
    // error C3867: 
}

Answer 1

如果我

理解正确，您想在Game对象上调用函数。这意味着您需要传递指向Game对象的指针，以便正确调用其上的非静态成员函数指针 （iChange）。

进行如下所示的更改，您应该能够执行所需的操作

enemies_array[0].enemy =  new Enemy(this,&Game::EnemyEvent);   
typedef void (Game::*ChangeFunc)(DWORD &)
Class Enemy
{
private:
   ChangeFunc iChange;
   Game *pGame;
}:
Enemy(Game *pCreatorGame, ChangeFunc iChangeHandler )
{
    iChange = iChangeHandler;
    pGame = pCreatorGame;
}
void Enemy::Draw(D3DGraphics& gfx)
{
    (pGame->*iChange)(this->dwThreadID);