函数名: gety

功 能: 返回当前图形位置的y坐标

用 法: int far gety(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;

char msg[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\", grapherrormsg(errorcode));

printf("Press any key to halt:");

getch();

exit(1); /* terminate with an error code */

}

/* move to the screen center point */

moveto(getmaxx() / 2, getmaxy() / 2);

/* create a message string */

sprintf(msg, "<-(%d, %d) is the here.", getx(), gety());

/* display the message */

outtext(msg);

/* clean up */

getch();

closegraph();

return 0;

}

函数名: gmtime

功 能: 把日期和时间转换为格林尼治标准时间(GMT)

用 法: struct tm *gmtime(long *clock);

程序例:

#include <stdio.h>

#include <stdlib.h>

#include <time.h>

#include <dos.h>

/* Pacific Standard Time & Daylight Savings */

char *tzstr = "TZ=PST8PDT";

int main(void)

{

time_t t;

struct tm *gmt, *area;

putenv(tzstr);

tzset();

t = time(NULL);

area = localtime(&t);

printf("Local time is: %s", asctime(area));

gmt = gmtime(&t);

printf("GMT is: %s", asctime(gmt));

return 0;

}

函数名: gotoxy

功 能: 在文本窗口中设置光标

用 法: void gotoxy(int x, int y);

程序例:

#include <conio.h>

int main(void)

{

clrscr();

gotoxy(35, 12);

cprintf("Hello world");

getch();

return 0;

}

函数名: gotoxy

功 能: 在文本窗口中设置光标

用 法: void gotoxy(int x, int y);

程序例:

#include <conio.h>

int main(void)

{

clrscr();

gotoxy(35, 12);

cprintf("Hello world");

getch();

return 0;

}

函数名: graphdefaults

功 能: 将所有图形设置复位为它们的缺省值

用 法: void far graphdefaults(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 maxx, maxy;

/* initialize graphics and local variables */

initgraph(&gdriver, &gmode, "c:\\\\bor\\\\Borland\\\\bgi");

/* read result of initialization */

errorcode = graphresult();

if (errorcode != grOk) /* an error occurred */

{

printf("Graphics error: %s\", grapherrormsg(errorcode));

printf("Press any key to halt:");

getch();

exit(1); /* terminate with an error code */

}

maxx = getmaxx();

maxy = getmaxy();

/* output line with non-default settings */

setlinestyle(DOTTED_LINE, 0, 3);

line(0, 0, maxx, maxy);

outtextxy(maxx/2, maxy/3, "Before default values are restored.");

getch();

/* restore default values for everything */

graphdefaults();

/* clear the screen */

cleardevice();

/* output line with default settings */

line(0, 0, maxx, maxy);

outtextxy(maxx/2, maxy/3, "After restoring default values.");

/* clean up */

getch();

closegraph();

return 0;

}

函数名: grapherrormsg

功 能: 返回一个错误信息串的指针

用 法: char *far grapherrormsg(int errorcode);

程序例:

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#define NONSENSE -50

int main(void)

{

/* FORCE AN ERROR TO OCCUR */

int gdriver = NONSENSE, gmode, errorcode;

/* initialize graphics mode */

initgraph(&gdriver, &gmode, "");

/* read result of initialization */

errorcode = graphresult();

/* if an error occurred, then output a */

/* descriptive error message. */

if (errorcode != grOk)

{

printf("Graphics error: %s\", grapherrormsg(errorcode));

printf("Press any key to halt:");

getch();

exit(1); /* terminate with an error code */

}

/* draw a line */

line(0, 0, getmaxx(), getmaxy());

/* clean up */

getch();

closegraph();

return 0;

}

函数名: graphresult

功 能: 返回最后一次不成功的图形操作的错误代码

用 法: int far graphresult(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;

/* initialize graphics and local variables */

initgraph(&gdriver, &gmode, "");

/* read result of initialization */

errorcode = graphresult();

if (errorcode != grOk) /* an error occurred */

{

printf("Graphics error: %s\", grapherrormsg(errorcode));

printf("Press any key to halt:");

getch();

exit(1); /* terminate with an error code */

}

/* draw a line */

line(0, 0, getmaxx(), getmaxy());

/* clean up */

getch();

closegraph();

return 0;

}

函数名: _graphfreemem

功 能: 用户可修改的图形存储区释放函数

用 法: void far _graphfreemem(void far *ptr, unsigned size);

程序例:

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include <alloc.h>

int main(void)

{

/* request auto detection */

int gdriver = DETECT, gmode, errorcode;

int midx, midy;

/* clear the text screen */

clrscr();

printf("Press any key to initialize graphics mode:");

getch();

clrscr();

/* initialize graphics and local variables */

initgraph(&gdriver, &gmode, "");

/* read result of initialization */

errorcode = graphresult();

if (errorcode != grOk) /* an error occurred */

{

printf("Graphics error: %s\", grapherrormsg(errorcode));

printf("Press any key to halt:");

getch();

exit(1); /* terminate with an error code */

}

midx = getmaxx() / 2;

midy = getmaxy() / 2;

/* display a message */

settextjustify(CENTER_TEXT, CENTER_TEXT);

outtextxy(midx, midy, "Press any key to exit graphics mode:");

/* clean up */

getch();

closegraph();

return 0;

}

/* called by the graphics kernel to allocate memory */

void far * far _graphgetmem(unsigned size)

{

printf("_graphgetmem called to allocate %d bytes.\", size);

printf("hit any key:");

getch();

printf("\");

/* allocate memory from far heap */

return farmalloc(size);

}

/* called by the graphics kernel to free memory */

void far _graphfreemem(void far *ptr, unsigned size)

{

printf("_graphfreemem called to free %d bytes.\", size);

printf("hit any key:");

getch();

printf("\");

/* free ptr from far heap */

farfree(ptr);

}