#include <string>
using namespace std;
//抽象圖表介面：抽象產品類
class Chart{
public:
	virtual void display()=0; 
};

//柱狀圖表：具體產品類
class HistogramChart :public Chart{
public:
	HistogramChart(){
		cout<<"建立柱狀圖"<<endl;
	}
	void display(){
		cout<<"顯示柱狀圖"<<endl;
	}
};

//餅狀圖表：具體產品類
class PipeChart:public Chart{
public:
	PipeChart(){
		cout<<"建立餅狀圖"<<endl;
	}
	void display(){
		cout<<"顯示餅狀圖"<<endl;
	}
};

//折線圖類：具體產品類
class LineChart:public Chart{
public:
	LineChart(){
		cout<<"建立折線圖"<<endl;
	}
	void display(){
		cout<<"顯示折線圖"<<endl;
	}
};

//圖表工廠類：工廠類
class ChartFactory{
public:
	static Chart* getChart(string arg){
		Chart *chart=NULL;
		int i=0;
		while(arg[i]){
			arg[i]=tolower(arg[i]);
			i++;
		}
		if(arg=="histogramchart"){
			cout<<"初始化設定柱狀圖"<<endl;
			chart=new HistogramChart();
		}
		else if(arg=="pipechart"){
			chart=new PipeChart();
			cout<<"初始化設定餅狀圖"<<endl;
		}
		else if(arg=="linechart"){
			chart=new LineChart();
			cout<<"初始化設定折線圖"<<endl;
		}
		return chart;
	}
};

int main(){
	Chart* chart=NULL;
	chart=ChartFactory::getChart("PipeChart");
	if(chart==NULL)
		cout<<"引數不正確"<<endl;
	else
		chart->display();
	return 0;
}
 

簡單工廠模式總結