从主 function 调用变量到其他类&无法使用这个？

Question

当所有类都放在一个包含所有类的主 cpp 文件中时，我能够运行该程序。 但是，当我将 cpp 文件拆分为各自的 header 文件和 cpp 文件时，出现了一些错误。

以下是我正在使用的所有文件（它们都在一个文件夹中）：

1) Assignment.cpp  (where the main function is at)
2) ShapeTwoD.cpp (Where the parent class is at)
3) ShapeTwoD.h
3) Square.cpp (Child Class)
4) Square.h
5) Rectangle.cpp (Child class)
6) Rectangle.h

问题一：

我有两个变量：

ShapeTwoD * Shape2D [100];

int size = 0;
   

以上变量主要在function中。 我尝试在其他类中调用上述变量，但是有一个错误表明它没有在 scope 中声明。 我也尝试添加 extern，但似乎也存在一些错误。 我已将变量移至父 class，Shape2D.cpp，但是，主 cpp 无法检测到变量名称。 我还公开了：在父 cpp 下。

如果有人可以帮助我，我将非常感激，因为我真的没时间了。 温馨问候

Square.h：

Square.cpp：

class Square: public ShapeTwoD{

    public:

    Square(string name, bool containsWarpSpace, vector < pair<int, int> > vect):ShapeTwoD(name,containsWarpSpace,vect,radius){

        this->vect = vect;
        this->name = name;
        this->containsWarpSpace = containsWarpSpace;


    }
    double computeArea();
    bool isPointOnShape(int x, int y);
    bool isPointInShape(int x, int y);
    vector<pair<int,int> >allCoord();
    void setInnerCoord(vector<pair<int,int> > innerCoord);
    vector<pair<int,int> > getInnerCoord();
    void setOuterCoord(vector<pair<int,int> > outerCoord);
    vector<pair<int,int> > getOuterCoord();
    string toString();
    void calculatePerimeter();

    ~Square(){

    }



};

double Square::computeArea(){

        int width;
        int area;

      std::vector< pair<int, int> >::iterator result = std::max_element(this->vect.begin(), this->vect.end());
      int positionMax = std::distance(this->vect.begin(), result);

       pair<int, int> maxCoordinate = this->vect[positionMax];



    for(int i = 0; i < this->vect.size(); i++){
        if(this->vect[i].second == maxCoordinate.second && this->vect[i] != maxCoordinate){
            width = maxCoordinate.first - this->vect[i].first;
            area = width * width;
        }

    }


    return area;
}

bool Square::isPointOnShape(int x, int y){
     bool result = false;

      std::vector< pair<int, int> >::iterator resultMax = std::max_element(this->vect.begin(), this->vect.end());
          int positionMax = std::distance(this->vect.begin(), resultMax);

          std::vector< pair<int, int> >::iterator resultMin = std::min_element(this->vect.begin(), this->vect.end());
          int positionMin = std::distance(this->vect.begin(), resultMin);

           pair<int, int> maxCoordinate = this->vect[positionMax];
           pair<int, int> minCoordinate = this->vect[positionMin];

           for(int i = 0; i < this->vect.size();i++){

               if(maxCoordinate.first == x || maxCoordinate.second == y || minCoordinate.first == x || minCoordinate.second == y){
                   result = true;
               }
               else{
                   result = false;
               }
           }




    return result;
}

ShapeTwoD.cpp（父类）：

class ShapeTwoD{

    protected:
    string name;
    bool containsWarpSpace;
    vector < pair<int, int> > vect;
    int radius;
    double area;
    vector < pair<int, int> > innerCoord;
    vector < pair<int, int> > outerCoord;




    private:


    public:

    ShapeTwoD(){


    }

    ShapeTwoD(string name, bool containsWarpSpace, vector < pair<int, int> > vect, int radius){
        this->radius = radius;
        this->vect = vect;
        this->name = name;
        this->containsWarpSpace = containsWarpSpace;

    }
    virtual double computeArea();
    virtual bool isPointInShape(int x, int y);
    virtual bool isPointOnShape(int x, int y);
    virtual vector<pair<int,int> > allCoord();
    virtual void setInnerCoord(vector<pair<int,int> > innerCord);
    virtual vector<pair<int,int> > getInnerCoord();
    virtual void setOuterCoord(vector<pair<int,int> > outerCoord);
    virtual vector<pair<int,int> > getOuterCoord();
    virtual string toString();
    virtual void calculatePerimeter();

    virtual ~ShapeTwoD(){

    }



    string getName();
    bool getContainsWarpSpace();





    void setName(string name);
    void setContainsWarpSpace(bool containsWarpSpace);


    void setCoord(vector < pair<int, int> > v);
    vector < pair<int, int> > getCoord();
    void setArea(double area);
    double getArea();


};

主功能（）：

int main() {

ShapeTwoD * obj;


int x;
int y;
int radius;

string menu = "0";

while(menu != "5"){
    cout <<"----------------------------------" << endl;
    cout << "1) Input sensor data" <<endl;
    cout << "5) Quit\n" <<endl;
    cout << "Please enter your choice:";
    cin >> menu;




if(menu == "1"){

cout << "[ Input sensor data ]" << endl;

    cout << "Please enter name of shape :";
    cin >> shape;
    transform(shape.begin(), shape.end(), shape.begin(), ::tolower);
    cout << "Please enter special type :";
    cin >> specialtype;
    transform(specialtype.begin(), specialtype.end(), specialtype.begin(), ::tolower);



 if(shape == "rectangle"){
     vector < pair<int, int> > temp;
    for(int i = 0; i < 4; i++){
                cout << "Please enter x-ordinate of pt " << i+1 <<" :";
                cin >> x;
                cout << "Please enter y-ordinate of pt " << i+1 << " :";
                cin >> y;

                  std::pair <int,int> p;
                  p = std::make_pair (x,y);
                  temp.push_back(p);

            }


    obj = new Rectangle(shape,"",temp);


      if(specialtype == "ws"){
          obj->setContainsWarpSpace(true);

 }
      else if (specialtype == "ns"){
          obj->setContainsWarpSpace(false);

      }

      Shape2D[size] = obj;
      size ++;
      temp.clear();



    cout << "\nRecords successfully stored. Going back to main menu ...\n" << endl;


    }
else if(shape == "square" ){

     vector < pair<int, int> > temp;

    for(int i = 0; i < 4; i++){
                cout << "Please enter x-ordinate of pt " << i+1 <<" :";
                cin >> x;
                cout << "Please enter y-ordinate of pt " << i+1 << " :";
                cin >> y;

                  std::pair <int,int> p;
                  p = std::make_pair (x,y);


                temp.push_back(p);


            }

    obj = new Square(shape,"",temp);


      if(specialtype == "ws"){
          obj->setContainsWarpSpace(true);

  }
      else if (specialtype == "ns"){
          obj->setContainsWarpSpace(false);

      }



      temp.clear();
      Shape2D[size] = obj;
      size ++;

    cout << "\nRecords successfully stored. Going back to main menu ...\n" << endl;




}


    cout << "\nRecords successfully stored. Going back to main menu ...\n" << endl;






}

Answer 1

对于问题一，最合乎逻辑的地方是 ShapeTwoD 中的ShapeTwoD成员。 将以下内容放入 shapetwod.h：

class ShapeTwoD {
  public:
    static vector<shared_ptr<ShapeTwoD>> allShapes;
};

并在 shapetwod.cpp 中定义：

vector<shared_ptr<ShapeTwoD>> ShapeTwoD::allShapes;

然后，您可以使用ShapeTwoD::allShapes从其他地方访问此向量。
注意：从 C++17 开始，您可以放弃额外的定义，并使声明inline static 。