|
Turbo C 2.0、Borland C++库函数及用例(19) 用 法: void far drawpoly( int numpoints,
int far *polypoints );
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; /* our polygon array */
int poly[10]; /* 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();
/* terminate with an error code */
exit(1);
}
maxx = getmaxx();
maxy = getmaxy(); poly[0] = 20; /* 1st vertext */
poly[1] = maxy / 2; poly[2] = maxx - 20; /* 2nd */
poly[3] = 20; poly[4] = maxx - 50; /* 3rd */
poly[5] = maxy - 20; poly[6] = maxx / 2; /* 4th */
poly[7] = maxy / 2;
/*
drawpoly doesn't automatically close
the polygon, so we close it.
*/ poly[8] = poly[0];
poly[9] = poly[1]; /* draw the polygon */
drawpoly(5, poly); /* clean up */
getch();
closegraph();
return 0;
}
函数名: dup
功 能: 复制一个文件句柄
用 法: int dup(int handle);
程序例:#include <string.h>
#include <stdio.h>
#include <conio.h>
#include <io.h>void flush(FILE *stream);int main(void)
{ FILE *fp;
char msg[] = "This is a test"; /* create a file */
fp = fopen("DUMMY.FIL", "w"); /* write some data to the file */
fwrite(msg, strlen(msg), 1, fp);
clrscr();
printf("Press any key to flush \
DUMMY.FIL:");
getch(); /* flush the data to DUMMY.FIL without
closing it */
flush(fp); printf("\nFile was flushed, Press any \
key to quit:");
getch();
return 0;
}void flush(FILE *stream)
{
int duphandle;
/* flush TC's internal buffer */
fflush(stream); /* make a duplicate file handle */
duphandle = dup(fileno(stream)); /* close the duplicate handle to flush the
|
