为什么出现这句话 BGI Error: Graphics not initialized (use 'initgraph')
											用TC运行时出现 BGI Error: Graphics not initialized (use 'initgraph')源码是
 程序代码:
程序代码:#include <stdio.h>
#include <graphics.h>/*加入c图形库*/
#include <math.h>
#include <conio.h>
yidong(int dx,int dy)/*实现移动函数*/
{
    moveto(320+dx,240-dy);
    lineto(420+dx,120-dy);
    lineto(450+dx,140-dy);
    lineto(320+dx,240-dy);/*变换三角形三个点的坐标实现移动变换*/
}
bilie(float Sx,float Sy) /*实现比例函数*/
{
    moveto(320*Sx,240*Sy);
    lineto(420*Sx,120*Sy);
    lineto(450*Sx,140*Sy);
    lineto(320*Sx,240*Sy); /*变换三角形三个点的坐标实现比列变换*/
}
xuanzhuan(float a) /*实现旋转函数*/
{
    float p;
    moveto(320,240);
    lineto(320+(420-320)*cos(a)-(240-120)*sin(a),240-(420-320)*sin(a)-(240-120)*cos(a));
    lineto(320+(450-320)*cos(a)-(240-140)*sin(a),240-(450-320)*sin(a)-(240-140)*cos(a));
    lineto(320,240); /*变换三角形三个点的坐标实现旋转变换*/
}
main()
{ 
    int i,j;
    float X,Y,bx,by,a;
    int gdriver=DETECT,gmode; /*初始化显示模式参数*/
 initgraph(&gdriver,&gmode,""); /*初始化显示为默认的640*480、16色模式 */
    
   i=20;
   j=240;
   moveto(i,j);
   for(i=20;i<=620;i+=20)           /*使用双循环画点函数画出表格中的纵坐标*/
   lineto(i,240);
   i=320;
   j=20;
   moveto(i,j);
   for(j=20;j<=460;j+=20)           /*使用双循环画点函数画出表格中的横坐标*/
   lineto(320,j);
   moveto(320,240);
   lineto(420,120);
   lineto(450,140);
   lineto(320,240);/*画出需变换的三角形,其三个顶点分别为(320,240); (420,120) ;(450,140)*/
   printf("please input X,Y to move:");
   scanf("%f%f",&X,&Y); /*输入移动量 */
   yidong(X,Y);
   printf("please input bx,by to scale:"); 
   scanf("%f%f",&bx,&by); /*输入x方向,y方向缩放大小 */
   bilie(bx,by);
   printf("please input a to circumgyrate:");
   scanf("%f",&a); /*输入旋转角度,a为正,则逆时针旋转*/
   xuanzhuan(a);
}										
					
	
 
											





 
	     
										
					
	 
 