目录
【程序56】题目：画图，学用circle画圆形
【程序57】题目：画图，学用line画直线。
【程序58】题目：画图，学用rectangle画方形。
【程序59】题目：画图，综合例子。
【程序60】题目：画图，综合例子。
【程序56】
题目：画图，学用circle画圆形
#include "graphics.h"
#include<conio.h>
int main()
{int i;float j = 1, k = 1;initgraph(640, 480);setbkcolor(YELLOW);cleardevice();for (i = 0;i <= 25;i++){setlinestyle(PS_SOLID, 4);setlinecolor(BLUE);circle(310, 250, k);k = k + j;j = j + 0.3;}_getch();closegraph();//关闭窗口
} 
【程序57】
题目：画图，学用line画直线。
#include "graphics.h"
#include<conio.h>
int main()
{int i;float x0, y0, y1, x1;float j = 12, k;initgraph(640, 480);setbkcolor(GREEN);cleardevice();x0 = 263;y0 = 263;y1 = 275;x1 = 275;for (i = 0;i <= 18;i++){setlinestyle(PS_SOLID, 4);setlinecolor(BLUE);line(x0, y0, x0, y1);x0 = x0 - 5;y0 = y0 - 5;x1 = x1 + 5;y1 = y1 + 5;j = j + 10;}x0 = 263;y1 = 275;y0 = 263;for (i = 0;i <= 20;i++){setlinestyle(PS_SOLID, 4);setlinecolor(BLUE);line(x0, y0, x0, y1);x0 = x0 + 5;y0 = y0 + 5;y1 = y1 - 5;}_getch();closegraph();//关闭窗口
} 
【程序58】
题目：画图，学用rectangle画方形。
程序分析：利用for循环控制100 - 999个数，每个数分解出个位，十位，百位。
#include <graphics.h>
#include<conio.h>
int main()
{int x0, y0, y1, x1, i;initgraph(640, 480);setbkcolor(YELLOW);cleardevice();x0 = 263;y0 = 263;y1 = 275;x1 = 275;for (i = 0;i <= 18;i++){setlinestyle(PS_SOLID, 4);setlinecolor(BLUE);rectangle(x0, y0, x1, y1);x0 = x0 - 5;y0 = y0 - 5;x1 = x1 + 5;y1 = y1 + 5;}setcolor(2);circle(269, 269, 137);_getch();closegraph();//关闭窗口
} 
【程序59】
题目：画图，综合例子。
# define PAI 3.1415926
# define B 0.809
# include "graphics.h"
#include "math.h"
#include<conio.h>
int main()
{int i, j, k, x0, y0, x, y;float a;initgraph(640, 480);setlinestyle(PS_SOLID, 3);setlinecolor(BLUE);setbkcolor(GREEN);cleardevice();x0 = 150;y0 = 100;circle(x0, y0, 10);circle(x0, y0, 20);circle(x0, y0, 50);for (i = 0;i < 16;i++){a = (2 * PAI / 16) * i;x = ceil(x0 + 48 * cos(a));y = ceil(y0 + 48 * sin(a) * B);setlinestyle(PS_SOLID, 3);setlinecolor(BLUE);line(x0, y0, x, y);}setcolor(3);circle(x0, y0, 60);/* Make 0 time normal size letters */_getch();setfillstyle(10, YELLOW);floodfill(202, 100, WHITE);_getch();for (k = 0;k <= 500;k++){setlinestyle(PS_SOLID, 4);setlinecolor(BLUE);for (i = 0;i <= 16;i++){a = (2 * PAI / 16) * i + (2 * PAI / 180) * k;x = ceil(x0 + 48 * cos(a));y = ceil(y0 + 48 + sin(a) * B);setlinestyle(PS_SOLID, 3);setlinecolor(BLUE);line(x0, y0, x, y);}for (j = 1;j <= 50;j++){a = (2 * PAI / 16) * i + (2 * PAI / 180) * k - 1;x = ceil(x0 + 48 * cos(a));y = ceil(y0 + 48 * sin(a) * B);line(x0, y0, x, y);}}restorecrtmode();_getch();closegraph();//关闭窗口
} 
【程序60】
题目：画图，综合例子。
#include "graphics.h"
#include<conio.h>
#define LEFT 0
#define TOP 0
#define RIGHT 639
#define BOTTOM 479
#define LINES 400
#define MAXCOLOR 15
int main()
{int error=0;int x1, y1;int x2, y2;int dx1, dy1, dx2, dy2, i = 1;int count = 0;int color = 0;initgraph(640, 480);x1 = x2 = y1 = y2 = 10;dx1 = dy1 = 2;dx2 = dy2 = 3;while (!_kbhit()){line(x1, y1, x2, y2);x1 += dx1;y1 += dy1;x2 += dx2;y2 + dy2;if (x1 <= LEFT || x1 >= RIGHT)dx1 = -dx1;if (y1 <= TOP || y1 >= BOTTOM)dy1 = -dy1;if (x2 <= LEFT || x2 >= RIGHT)dx2 = -dx2;if (y2 <= TOP || y2 >= BOTTOM)dy2 = -dy2;if (++count > LINES){setlinestyle(PS_SOLID, 0);setlinecolor(BLUE);color = (color >= MAXCOLOR) ? 0 : ++color;}}closegraph();_getch();closegraph();//关闭窗口
}
