【发布时间】：2020-08-14 08:50:38
【问题描述】：
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文件拆分为各自的头文件和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 1：
我有两个变量：
ShapeTwoD * Shape2D [100];
int size = 0;
以上变量在main函数中。我已经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范围内声明。我也尝试添加 extern，但似乎也存在一些错误。我已将变量移至父类 Shape2D.cpp，但是，主 cpp 无法检测到变量名称。我也放在 public: 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。最热烈的问候
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();
};
主函数()：
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;
}
【问题讨论】：
-
你能放置sn-ps的代码来显示所涉及的主要文件吗？
-
对于问题 1：重新阅读 C++ 教科书的“静态变量”部分（也可以使用
std::vector<ShapeTwoD*>。对于问题 2：显示代码。 -
为什么不能在 Shape2D 子类中访问
this->vect？你得到什么错误？此外，c++ 编译器现在可以处理嵌套模板一段时间，您不再需要插入额外的空格。 -
另外，如果完整的类声明在你的 CPP 文件中，你的头文件中有什么？
-
Class Square 没有名为“vect”的成员
标签： c++ variables inheritance