Question

c++求大神帮我看看为什么这个程序运行不了？关于图形工厂总是出现redefinition of 'class BaseShape'

源程序代码如下：
// BaseShape.h文件
#include <iostream>
using namespace std;

class BaseShape {

public:
BaseShape() {};
virtual ~BaseShape() {};

virtual void DrawShape() = 0;
};

//*********************************
//ShapeFactory.h文件

#include <fstream>
#include <string>
#include "Line.h"
#include "BaseShape.h"

//定义工厂类
class ShapeFactory{

public:
ShapeFactory();
~ShapeFactory();

//BaseShape* SelectShape(string);
BaseShape* SelectShape(string shape) {

if(shape=="Line" || shape=="线")return new Line();
else cout<< "输入的图形名称错误！" <<endl;
}
};

// ShapeFactory.cpp文件
#include "ShapeFactory.h"

ShapeFactory::ShapeFactory(void)
{}

ShapeFactory::~ShapeFactory(void)
{}
//********************************************
// Line.h文件
///////////////////直线Line/////////////////////

#include "BaseShape.h"

class Line : public BaseShape {

private:
int n;
static int L;
public:
Line() {};
virtual ~Line() {};
//构造函数成员初始化列表，构造函数之后，函数体之前。
Line ( int n) : n(n) { }
//覆盖抽象类的纯虚函数
virtualvoid DrawShape();
};

// Line.cpp文件
#include "Line.h"
//绘制直线
void Line ::DrawShape() {

int n;
static int L;
cout<< "请选择直线长度： " <<endl;
cin>> n;
for(int i=0; i<n; i++) {

cout<< "*" ;
}
L++;
cout<<endl<< "^_^ 您已经绘制"<< L << "条直线^_^ "<<endl;

}
//********************************************
**********************************************

*********************************************
#include <fstream>
#include <vector>
#include <string>
#include "Line.h"
#include "BaseShape.h"
#include "ShapeFactory.h"

#include <iostream>
using namespace std;

int main() {

/*

读infile类 的文件ShapeFactoryFile.txt中可绘制的图形并为每行加上"行号-"，输出到运行屏幕上。

*/
ifstream infile("ShapeFactoryFile.txt");

if(!infile) {//检验文件是否成功打开

cout<< "sorry! Unable to open ShapeFactoryFile. " <<endl;
return -1;

}

string line;
vector<string> text;

while (getline(infile,line)) {

text.push_back(line);

}

for(int j=0; j<text.size(); j++)
cout<< j+1 << " - " << text[j] <<endl;

cout<<endl << "*************以上是可以绘制的图形名***************" <<endl<<endl;

//定义工厂对象、基类指针
ShapeFactory factory;
BaseShape * pBaseShape;

string shape;
int t=0;
while(true) {

cout<<"请输入图形（英文或中文）名称（以#为结束程序）: ";
cin>>shape;
if(shape=="#") break;

BaseShape* pBaseShape=factory.SelectShape(shape);//选择具体类
pBaseShape->DrawShape();//调用具体类的画法
delete pBaseShape;

t++;
cout<< "您总共已经输出"<< t <<"个图形。" <<endl;
}

return 0;
}

Answer 1

如果你没饥扮洞用预编译宏或者#pragma once就缺拦是头文件重复引用
每个类烂枯的头文件最开始都加上
#pragma once