Question

当我尝试设置

时

cub.SetArray(cube);

我收到错误

Console Application1.exe has triggered a breakpoint

我做错了什么？当我尝试调试cub -> cubesarray时，我得到大小-842150451。我不明白为什么。这是我的全部代码

class Cube{
public:
    static const int Change_ARRAY = 5;

private:
    string color;
    int size;
    int *walls;
    int n; // current size of array
    int maximumsize; // maximum size of array
    void Increase(int many);
public:
    Cube(int maximumsize = 0);
    ~Cube();
    void SetWalls(int wall);
    void SetColor(string color);
    void SetSize(int size);

    string GetColor(){return color;}
    int GetWalls(int i){return walls[i];}
    int GetSize(){return size;}

    int GetN(){return n;}
};

Cube::Cube(int maximumsize):n(0), maximumsize(maximumsize), size(size), walls(NULL){
    if(maximumsize > 0){
        walls = new int[maximumsize];
    }
}

Cube::~Cube(){
    if(walls){
        delete [] walls;
    }
}

void Cube::Increase(int many){
    if(many > maximumsize){
        int *newest = new int[many];
        for(int i=0; i<n; i++)
            newest[i] = walls[i];
        delete [] walls;
        walls = newest;
        maximumsize = many;
    }else if( many < maximumsize){
        int *newest = new int[many];
        for(int i=0; i<many; i++)
            newest[i] = walls[i];
        delete [] walls;
        walls = newest;
        n = maximumsize = many;
    }
}

void Cube::SetWalls(int wall){
    if(n == maximumsize) Increase(n + Change_ARRAY);
    walls[n] = wall;
    n++;
}

void Cube::SetColor(string color){
    this->color = color;
}

void Cube::SetSize(int size){
    this->size = size;
}

class CubesArray{
public:
    static const int Change_Array = 5;
private:
    Cube *cubesarray;
    int currentsize; // current size of array
    int maxsize; // maximumsize
    void Change (int kk);
public:
    CubesArray(int maxsize = 1);
    ~CubesArray();

    void SetArray(Cube c);
    Cube GetArray(int ind){return cubesarray[ind];}
    int GetCsize(){return currentsize;}
};

CubesArray::CubesArray(int maxsize):cubesarray(NULL), currentsize(0), maxsize(maxsize){
    if(maxsize > 0){
        cubesarray = new Cube[maxsize];
    }
}

CubesArray::~CubesArray(){
    if(cubesarray){
        delete [] cubesarray;
    }
}

void CubesArray::Change(int kk){
    if(kk > maxsize){
        Cube *newarr = new Cube[kk];
        for(int i=0; i<currentsize; i++)
            newarr[i] = cubesarray[i];
        delete [] cubesarray;
        cubesarray = newarr;
        maxsize = kk;
    }if(kk < maxsize){
        Cube *newarr = new Cube[kk];
        for(int i=0; i<kk; i++)
            newarr[i] = cubesarray[i];
        delete [] cubesarray;
        cubesarray = newarr;
        currentsize = maxsize = kk;
    }
}

void CubesArray::SetArray(Cube cub){
    if(currentsize = maxsize) Change(currentsize + Change_Array);
    cubesarray[currentsize] = cub;
    currentsize++;
}

void Read(CubesArray & cub);

int main(){
    CubesArray cub;

    Read(cub);

    system("pause");
    return 0;
}

void Read(CubesArray & cub){
    string color;
    int size;
    int i=0;
    Cube cube;
    ifstream fd(Data);
    while(!fd.eof()){
        fd >> color >> size;
        cube.SetSize(size);
        cube.SetColor(color);
        cout << cube.GetColor() << " " << cube.GetSize() << " ";
        while(fd.peek() != '\n' && !fd.eof()){
            int w;
            fd >> w;
            cube.SetWalls(w);
            cout << cube.GetWalls(i) << " ";
            cub.SetArray(cube); // when I set cube to cub I get this error!!!
            i++;
        }
        cout << endl;
        fd.ignore();
    }
}

Answer 1

变化：

if(currentsize = maxsize)

要：

if(currentsize == maxsize)

此外，这是您真正的问题：

class Cube中没有复制构造函数，因此每当您按值发送walls实例时，Cube数组都不会被正确复制，例如cub.SetArray(cube)。< / p>

您必须按如下方式定义：

Cube::Cube(const Cube& cube):n(cube.n),maximumsize(cube.maximumsize),size(cube.size),wall(NULL)
{
    if (maximumsize > 0)
    {
        walls = new int[maximumsize];
        for (int i=0; i<maximumsize; i++)
            wall[i] = cube.wall[i];
    }
}

并且class Cube中没有赋值运算符，因此每当您将一个walls实例分配给另一个Cube实例时，cubesarray[currentsize] = cub数组就不会被正确复制，例如Cube& Cube::operator=(const Cube& cube) { n = cube.n; maximumsize = cube.maximumsize; size = cube.size; wall = NULL; if (maximumsize > 0) { walls = new int[maximumsize]; for (int i=0; i<maximumsize; i++) wall[i] = cube.wall[i]; } return *this; }。

您必须按如下方式定义：

Cube::Cube(const Cube& cube)
{
    if (this != &cube)
        *this = cube;
}

BTW，在复制构造函数中，您只需调用赋值运算符（删除编码冗余）：

{{1}}

Answer 2

你的Cube类违反了三条规则。看这里：

   void CubesArray::SetArray(Cube cub){  // calls copy constructor

该调用会创建Cube类的副本。您的Cube类无法安全地复制。请参阅此处并向下滚动到管理资源部分：What is The Rule of Three?

您应该通过引用或const引用传递Cube，而不是按值传递。这样做可以更正你现在的错误，但是，你的班级仍然有问题。

C ++控制台Application1.exe已触发断点

2 个答案: