引发了C ++读取访问冲突错误，但是我不确定为什么。 瓷砖滑块益智游戏

Question

So I'm coding an object oriented Tile Slider Puzzle game, and I feel as though I've coded things correctly, and when I build the project, no errors are thrown. However, when I go to run my code (Visual Studio 2015 IDE) I get a message box saying the .exe file has stopped working. Here are my files thus far:

The following is the TileSlider.h file:

#ifndef TILESLIDER_H
#define TILESLIDER_H
#include <Windows.h>

class TileSlider
{
private:
    char** solvedBoard;
    char** gameBoard;

    //mutator(s)
    void setUpBoards(); //keep or copy code to constructor

    //other member functions
    void printBoard(const HANDLE &consoleOut) const; 
    void scrambleBoard();
    bool isBoardSolved() const;
    void makeMove(int move);

public:
    TileSlider();   //allocate mem here? maybe call setUpBoards()
   ~TileSlider();   //deallocate mem here

    void playGame();
};

#endif

The following is the TileSlider.cpp file:

#include "TileSlider.h"
using namespace std;

#define SIZE 3      //num of rows and cols to board

// --------------------------------------
//            Private Members
// --------------------------------------

// Mutator(s)
void TileSlider::setUpBoards() {
    //allocate memory for boards
    char** solvedBoard = new char*[SIZE];   
    char** gameBoard = new char*[SIZE];
    for (int i = 0; i < SIZE; i++) {
        solvedBoard[i] = new char[SIZE];
        gameBoard[i] = new char[SIZE];
    }

    //fill the boards
    char i = 49;  // ASCII code for '1'
    for (int row = 0; row < SIZE; row++) {
        for (int column = 0; column < SIZE; column++) {
            gameBoard[row][column] = i;
            solvedBoard[row][column] = i;
            i++;
        }
    }
    gameBoard[SIZE - 1][SIZE - 1] = 42; // ASCII for '*'
    solvedBoard[SIZE - 1][SIZE - 1] = 42;
}

The following is the driver file for my code (TileSliderGame.cpp):

#include "TileSlider.h"
using namespace std;

int main() {
    TileSlider* game = new TileSlider();
    game->playGame();
    delete game;
    return 0;
}

To attempt to determine the issue that was occurring, I put a break point to step into where I'm calling playGame() in the driver file (TileSliderGame.cpp). I stepped into that function, and then stepped into where playGame() calls the printBoard(consoleOut) function and I received a Read Access Violation error when I got to this line:

// Other Private Member Functions
void TileSlider::printBoard(const HANDLE &consoleOut) const {
    for (int row = 0; row < SIZE; row++) {
        for (int column = 0; column < SIZE; column++) {
            if (gameBoard[row][column] == 42) { //ASCII code 42 is '*' asterisk
. . .

(The error was thrown at the last line shown above) Error message:

Exception thrown: read access violation.

this->gameBoard was 0x1110112.

Now, I'm really not sure why I would get a read access violation error within the printBoard() function because it's a private function, and therefore should be able to directly access the private gameBoard variable inside the class. I even tried to see if it would make a difference to create an accessor for the gameBoard, but it didn't (the same error was thrown).

Another note I'd like to make, I started this code in a separate project with an Imperative program design and have got it running as I intend it to. Therefore, I know that the code within my object oriented program regarding how the TileSlider game works is working perfectly fine. I'm just not sure what I may have done wrong when I redesigned the code into an object oriented design.

If what my game is supposed to look like is confusing, the TileSlider gameBoard is a 3x3 2D character array that displays onto the screen like so :

1 2 3
4 5 6
7 8 *

Above is how the gameBoard starts, it is then scrambled and the user then moves the tiles with the "wasd" keys to attempt to win the game. Any tiles moved into their correct position (the positions showed above) are colored green, and any tiles that aren't in their correct position are colored red. The one exception is that the empty tile (the asterisk) is printed in white all of the time.

I don't think that my code is perfect so I'll take any constructive criticism on my code and code design that I can get.

Edit: I removed a large portion of my TileSlider.cpp file code shown above because it was irrelevant to the error I made in my code.

Answer 1

You wrote:

char** solvedBoard = new char*[SIZE];   
char** gameBoard = new char*[SIZE];

You probably meant:

solvedBoard = new char*[SIZE];   
gameBoard = new char*[SIZE];

The reason is that your declaration of solvedBoard and gameBoard in TileSlider::setUpBoards() effectively hides the TileSlider member variables with the same names, and nothing is assigned to the latter.