1 #include <iostream>
 2 #include "canvas.h"
 3 #include "ball.h"
 4 
 5 int main() {
 6     Canvas canvas; //创建默认画布，黑底绿色
 7     
 8     Ball ball1(10,10);
 9     system("pause");
10     
11     ball1.left(5);
12     system("pause");
13     
14     ball1.up(20);
15     system("pause");
16 
17     canvas.changeCanvasFg("E"); // 更新画布前景色
18     system("pause");
19     
20     canvas.changeCanvasBg("D"); // 更新画布背景色
21     system("pause");
22 
23     return 0;
24 }

#ifndef CANVAS_H
#define CANVAS_H

#include <string>
using std::string;

class Canvas {
    public:
        Canvas(string bg0="0", string fg0="A");
        void changeCanvasBg(string bg0);
        void changeCanvasFg(string fg0);
        void changeCanvasColor(string bg0, string fg0); 
    private:
        string bg;   // background color
        string fg;   // foreground color 
};

#endif

 1 #include "canvas.h"
 2 #include <cstdlib>
 3 Canvas::Canvas(string bg0, string fg0):bg(bg0), fg(fg0) {
 4     string color = "color ";
 5     color += bg0;
 6     color += fg0;
 7     system(color.c_str());
 8 }
 9 void Canvas::changeCanvasBg(string bg0) {
10     bg = bg0; // 更新画布背景色
11     string color = "color ";
12     color += bg;
13     color += fg;
14     system(color.c_str());
15 }
16 void Canvas::changeCanvasFg(string fg0) {
17     fg = fg0; // 更新画布前景色
18     string color = "color ";
19     color += bg;
20     color += fg;
21     system(color.c_str());
22 }
23 void Canvas::changeCanvasColor(string bg0, string fg0){
24     bg = bg0; // 更新画布背景色
25     fg = fg0; // 更新画布前景色
26     string color = "color ";
27     color += bg;
28     color += fg;
29     system(color.c_str());
30 }