函数名: getmaxcolor 
 功  能: 返回可以传给函数setcolor的最大颜色值 
 用  法: #include <graphics.h> 
         int far getmaxcolor(void); 
 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; 
    int midx, midy; 
    char colstr[80]; 
   /* 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(); 
       exit(1); /* terminate with an error code */ 
    } 
   midx = getmaxx() / 2; 
    midy = getmaxy() / 2; 
   /* grab the color info. and convert it to a string */ 
    sprintf(colstr, "This mode supports colors 0..%d", getmaxcolor()); 
   /* display the information */ 
    settextjustify(CENTER_TEXT, CENTER_TEXT); 
    outtextxy(midx, midy, colstr); 
   /* clean up */ 
    getch(); 
    closegraph(); 
    return 0; 
 }