函数名: getarccoords 
 功  能: 取得最后一次调用arc的坐标 
 用  法: #include <graphics.h> 
         void far getarccoords(struct arccoordstype far *arccoords); 
 程序例: 
#include <graphics.h> 
 #include <stdlib.h> 
 #include <stdio.h> 
 #include <conio.h> 
int main(void) 
 { 
 /* request auto detection */ 
    int gdriver = DETECT, gmode, errorcode; 
    struct arccoordstype arcinfo; 
    int midx, midy; 
    int stangle = 45, endangle = 270; 
    char sstr[80], estr[80]; 
/* initialize graphics and local variables */ 
    initgraph(&gdriver, &gmode, ""); 
/* read result of initialization */ 
    errorcode = graphresult(); 
 /* an error occurred */ 
    if (errorcode != grOk) 
    { 
       printf("Graphics error: %s\n", 
              grapherrormsg(errorcode)); 
       printf("Press any key to halt:"); 
       getch(); 
 /* terminate with an error code */ 
       exit(1); 
    } 
   midx = getmaxx() / 2; 
    midy = getmaxy() / 2; 
/* draw arc and get coordinates */ 
    setcolor(getmaxcolor()); 
    arc(midx, midy, stangle, endangle, 100); 
    getarccoords(&arcinfo); 
/* convert arc information into strings */ 
    sprintf(sstr, "*- (%d, %d)", 
            arcinfo.xstart, arcinfo.ystart); 
    sprintf(estr, "*- (%d, %d)", 
            arcinfo.xend, arcinfo.yend); 
   /* output the arc information */ 
    outtextxy(arcinfo.xstart, 
              arcinfo.ystart, sstr); 
    outtextxy(arcinfo.xend, 
              arcinfo.yend, estr); 
   /* clean up */ 
    getch(); 
    closegraph(); 
    return 0; 
 }