功 能： 畫一個二維條形圖
用 法： void far bar(int left,int top,int right,int bottom);
程式例：
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
int main(void)
{
/* request auto detection */
int gdriver = DETECT,gmode,errorcode;
int midx,midy,i;
/* initialize graphics and local variables */
initgraph(&gdriver,&gmode,"");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n",grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit⑴； /* terminate with an error code */
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* loop through the fill patterns */
for (i=SOLID_FILL; i<USER_FILL; i++)
{
/* set the fill style */
setfillstyle(i,getmaxcolor());
/* draw the bar */
bar(midx-50,midy-50,midx+50,
midy+50）；
getch();
}
/* clean up */
closegraph();
return 0;
}
