Visual C++和Allegro5：無法從頭文件中識別抽象類中的對象

Question

我是一名初學者，並且不太熟悉C++，但我對這門語言有所瞭解，因此我希望編寫一款國際象棋遊戲。但是因爲我想在這個遊戲中使用圖像，所以我研究了Allegro 5進行編程。我想出了一個（不完全當然）頭文件到遊戲中的每個棋子初始化：

Piece.h

#pragma once 
#include <allegro5/allegro.h> 
#include <allegro5/allegro_native_dialog.h> 
#include <allegro5/allegro_primitives.h> 
#include <allegro5/allegro_image.h> 
#include <iostream> 
#include <string> 

using namespace std; 

class Piece 
{ 
    private: 

     int pieceX; 
     int pieceY; 
     bool inGame; 
     char pieceColor; 
     string imgAddress; 
     ALLEGRO_BITMAP *pieceImage; 

    public: 

     Piece(int pieceX, int pieceY, bool inGame, char pieceColor, string imgAddress) 
     { 
      this->pieceX = pieceX; 
      this->pieceY = pieceY; 
      this->inGame = inGame; 
      this->pieceColor = pieceColor; 
      this->imgAddress = imgAddress; 
      pieceImage = al_load_bitmap(imgAddress.c_str()); 
     } 

     int getPieceX() 
     { 
      return pieceX; 
     } 

     int getPieceY() 
     { 
      return pieceY; 
     } 

     bool isInGame() 
     { 
      return inGame; 
     } 

     char getPieceColor() 
     { 
      return pieceColor; 
     } 

     string getImageAddress() 
     { 
      return imgAddress; 
     } 

     void setPieceX(int newx) 
     { 
      pieceX = newx; 
     } 

     void setPieceY(int newy) 
     { 
      pieceY = newy; 
     } 

     void setinGame(bool newingame) 
     { 
      inGame = newingame; 
     } 

     void setImageAddress(string newimgaddr) 
     { 
      imgAddress = newimgaddr; 
     } 

     void reloadImage() 
     { 
      pieceImage = al_load_bitmap(imgAddress.c_str()); 
     } 

     Piece(void) 
     { 

     } 

     ~Piece(void) 
     { 

     } 

}; 

和其他一切將在主類，國際象棋處理。 CPP

#include <allegro5/allegro.h> 
#include <allegro5/allegro_native_dialog.h> 
#include <allegro5/allegro_primitives.h> 
#include <allegro5/allegro_image.h> 
#include "Piece.h" 
#include <iostream> 
#include <string> 
#include <cstring> 

using namespace std; 

const int SIDELENGTH = 50; 
const int ROWCOLSPAN = 8; 
const int WINDOW_WIDTH = (SIDELENGTH * ROWCOLSPAN) + 240; 
const int WINDOW_HEIGHT = (SIDELENGTH * ROWCOLSPAN) + 40; 
const float FPS = 60; 
const int MAXPIECES = ROWCOLSPAN * 2; 
const int MAXSPACES = ROWCOLSPAN * ROWCOLSPAN; 

setupBoard(Piece [MAXPIECES], Piece [MAXPIECES], char [MAXSPACES]); 

int main() 
{ 
    ALLEGRO_DISPLAY *gameDisplay; 

    if (!al_init()) cout << "Failed to load Allegro 5 for Chess++..." << endl; 

    gameDisplay = al_create_display(WINDOW_WIDTH, WINDOW_HEIGHT); 
    al_set_window_title(gameDisplay, "Chess++"); 

    if (!gameDisplay) cout << "Couldn't create Allegro 5 display for Chess++..." << endl; 

    al_init_primitives_addon(); //allows to load primitives 
    al_install_keyboard(); //allows for keyboard use*/ 
    al_install_mouse(); //installs the mouse to be able to use it 
    al_init_image_addon(); //prepares image loading 

    ALLEGRO_EVENT_QUEUE *gameQueue = al_create_event_queue(); //queue that receives events and acts them in order 
    al_register_event_source(gameQueue, al_get_keyboard_event_source()); //registers keyboard events to be recognized within event_queue 

    ALLEGRO_KEYBOARD_STATE keyState; 
    ALLEGRO_TIMER *gameTimer = al_create_timer(1.0/FPS); 

    al_register_event_source(gameQueue, al_get_keyboard_event_source()); //registers keyboard events to be recognized within event_queue 
    al_register_event_source(gameQueue, al_get_timer_event_source(gameTimer)); //registers a timer to work within event_queue 
    al_register_event_source(gameQueue, al_get_display_event_source(gameDisplay)); //registers the window to be able to give it events 
    al_register_event_source(gameQueue, al_get_mouse_event_source()); //register the installed mouse 

    bool gameOver = false; 
    bool draw = false; 
    bool quitclose = false; 

    int X = 0; 
    int Y = 0; 

    Piece blackPieces[MAXPIECES]; 
    Piece whitePieces[MAXPIECES]; 

    //The 8 by 8 board with the pieces; lowercase for black, uppercase for white 
    char chessboard[] = "rnbqkbnr\n" 
         "pppppppp\n" 
         "--------\n" 
         "--------\n" 
         "--------\n" 
         "--------\n" 
         "--------\n" 
         "PPPPPPPP\n" 
         "RNBQKBNR"; 

    //setupBoard(blackPieces, whitePieces, chessboard); 

    al_start_timer(gameTimer); //starts the specified timer 

    gameloop: 
    while(!gameOver) 
    { 
     ALLEGRO_EVENT gameEvents; //create receiver for events 
     al_wait_for_event(gameQueue, &gameEvents); //waits for an event from event_queue to be passed on to ALLEGRO_EVENT events 

     if (gameEvents.type == ALLEGRO_EVENT_KEY_UP/*DOWN*/) 
     { 

     } 
     else if (gameEvents.type == ALLEGRO_EVENT_DISPLAY_CLOSE) 
     { 
      quitclose = true; 
      gameOver = true; 
     } 
     else if (gameEvents.type == ALLEGRO_EVENT_MOUSE_AXES) //determines the movement of the mouse coordinates 
     { 

     } 
     else if (gameEvents.type == ALLEGRO_EVENT_MOUSE_BUTTON_DOWN) //if a mouse button is pressed 
     { 

     } 

     if (gameEvents.type == ALLEGRO_EVENT_TIMER) 
     { 
      draw = true; 
     } 

     if (draw) 
     { 
      draw = false; 

      int squareX = 20; 
      int squareY = 20; 
      bool colorchange = true; 
      for (int i = 1; i <= MAXSPACES;i++) 
      {    
       ALLEGRO_COLOR squarecolor = al_map_rgb(255, 255, 255); 
       if (!colorchange) squarecolor = al_map_rgb(0, 100, 0); 

       al_draw_filled_rectangle(squareX, squareY, squareX + SIDELENGTH, squareY + SIDELENGTH, squarecolor); 
       squareX += SIDELENGTH; 
       if (i % ROWCOLSPAN != 0) colorchange = !colorchange; 

       if (i % ROWCOLSPAN == 0) 
       { 
        squareY += SIDELENGTH; 
        squareX = 20; 
       } 

      } 

      al_flip_display();   
      al_clear_to_color(al_map_rgb(0, 0, 0)); //clears the canvas (display) like Java's repaint() 
     } 

    } 

    if (quitclose) 
    { 
     int quit = al_show_native_message_box(gameDisplay, "CHES++: QUIT", "ARE YOU SURE YOU WANNA QUIT?", "Please select YES or NO", NULL, ALLEGRO_MESSAGEBOX_YES_NO); 
     if (quit == 0) 
     { 
      gameOver = false; 
      goto gameloop; 
     } 
    } 

    al_destroy_display(gameDisplay); 

    /*cin.sync(); 
    cout << "\n\nPress any key to finish..."; 
    cin.get();*/ 
    return 0; 
} 

void setupBoard(Piece bp[MAXPIECES], Piece wp[MAXPIECES], char cb[]) 
{ 
    int barrindex = 0; 
    int warrindex = 0; 
    int x = 20; 
    int y = 20; 

    for (int i = 0; i < MAXSPACES; i++) 
    { 
     if (cb[i] == 'r') 
     { 
      bp[barrindex] = new Piece(x, y, true, 'b', "images/br.png"); 
      barrindex++; 
      x += SIDELENGTH; 
     }  
     if (cb[i] == 'n') 
     { 
      bp[barrindex] = new Piece(x, y, true, 'b', "images/bn.png"); 
      barrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'b') 
     { 
      bp[barrindex] = new Piece(x, y, true, 'b', "images/bb.png"); 
      barrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'q') 
     { 
      bp[barrindex] = new Piece(x, y, true, 'b', "images/bq.png"); 
      barrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'k') 
     { 
      bp[barrindex] = new Piece(x, y, true, 'b', "images/bk.png"); 
      barrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'p') 
     { 
      bp[barrindex] = new Piece(x, y, true, 'b', "images/bp.png"); 
      barrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'R') 
     { 
      wp[warrindex] = new Piece(x, y, true, 'w', "images/wr.png"); 
      warrindex++; 
      x += SIDELENGTH; 
     }  
     if (cb[i] == 'N') 
     { 
      wp[warrindex] = new Piece(x, y, true, 'w', "images/wn.png"); 
      warrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'B') 
     { 
      wp[warrindex] = new Piece(x, y, true, 'w', "images/wb.png"); 
      warrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'Q') 
     { 
      wp[warrindex] = new Piece(x, y, true, 'w', "images/wq.png"); 
      warrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'K') 
     { 
      wp[warrindex] = new Piece(x, y, true, 'w', "images/wk.png"); 
      warrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == 'P') 
     { 
      wp[warrindex] = new Piece(x, y, true, 'w', "images/wp.png"); 
      warrindex++; 
      x += SIDELENGTH; 
     } 
     if (cb[i] == '-') 
     { 
      x += SIDELENGTH; 
     } 
     if (cb[i] == '\n') 
     { 
      y += SIDELENGTH; 
      x = 20; 
     } 
    } 
} 

之前添加setupBoard（）函數和兩個物品（blackPieces和whitePieces），我的程序將運行，它會顯示一個漂亮的「棋盤」，這是用快板的原始基本上64畫正方形庫，所以我想我已經安裝了庫和正確的驅動。但我得到的錯誤是我夠不着的地方：

1. 首先，setupBoard是無效的，只是爲了修改其他變量來組織代碼。然而，智能感知給我一個錯誤：this declaration has no storage class or type specifier

2. 我不#include "Piece.h"得到一個錯誤，但在陣列blackPieces和whitePieces的聲明，我得到identifier "Piece" is undefined

3. 裏面的setupBoard功能在底部Chess.cpp，我通過char數組cb讀取，它來自棋盤，它具有特定的字符以將棋子放置在棋盤上。和取決於哪個字符，一塊對象被動態地分配給其相應的片陣列，這樣的：

bp[barrindex] = new Piece(x, y, true, 'b', "images/br.png");

然後整數控制該板的x和y被相應地增加以繪製他們在不同的地方。然而，雖然有似乎除了new Piece(，我猜是因爲錯誤2沒有錯誤，我得到這個錯誤：

error C2679: binary '=' : no operator found which takes a right-hand operand of type 'Piece *' (or there is no acceptable conversion) 

我敢肯定，我一定是錯誤的分配，但我不知道怎麼樣，我從來沒有這種錯誤。現在，我總是可以嘗試用Java或C＃做一個國際象棋遊戲，但是我想用C++做一些類似的遊戲（我認爲邏輯是讓人工智能與語言知識無關）。請，如果有人知道如何解決這些錯誤，我會非常感謝！

Answer 1

setupBoard(Piece [MAXPIECES], Piece [MAXPIECES], char [MAXSPACES]); 

您需要在前面的void。

這些都是不同的事情：

Piece bp[MAXPIECES] 
Piece* bp[MAXPIECES] 

你有它的樣子，你需要這樣做：

wp[warrindex] = Piece(x, y, true, 'w', "images/wn.png"); 

要了解兩者之間的差異，堆棧VS堆在讀了內存分配。您真的可能想要通過Piece* bp[MAXPIECES]使用堆並保留您的new調用。