这是我编的时钟程序，为什么指针有时会闪烁，我知道应该用双缓冲，但要怎么写啊，请各位大神说一下。。。
#include<stdio.h>
#include"graphics.h"
#include<time.h>
#include<conio.h>
#include"math.h"
#include"dos.h"
#define pi 3.1415926
void set1()//画外围圈
{
setcolor(YELLOW);
setlinestyle(0,0,3);
circle(300,240,200);
setcolor(WHITE);
circle(300,240,220);
setfillstyle(1,3);
pieslice(300,30,0,360,10);
setfillstyle(1,2);
pieslice(300,450,0,360,10);
}
void set2()//画刻盘
{
int i,l,x1,x2,y1,y2;
for(i=0;i<60;i++)
{
if(i%5==0)
l=15;
else
l=5;
x1=200*sin(i*6*pi/180)+300;
y1=200*cos(i*6*pi/180)+240;
x2=(200-l)*sin(i*6*pi/180)+300;
y2=(200-l)*cos(i*6*pi/180)+240;
setcolor(YELLOW);
line(x1,y1,x2,y2);
}
}
void set3()//填数字
{
setcolor(GREEN);
settextstyle(0,0,2);
outtextxy(290,80,"12");
outtextxy(375,100,"1");
outtextxy(430,160,"2");
outtextxy(460,230,"3");
outtextxy(430,310,"4");
outtextxy(380,370,"5");
outtextxy(295,390,"6");
outtextxy(220,370,"7");
outtextxy(160,310,"8");
outtextxy(140,230,"9");
outtextxy(157,155,"10");
outtextxy(215,95,"11");
}
int main()
{
int drive,mode;
int n1,n2,n3,h1,m1,s1,h2,m2,s2;
struct time *p;
drive=DETECT;
initgraph(&drive,&mode,"");
cleardevice();
set1();
set2();
set3();
while(!kbhit())
{
time_t t;
t=time(NULL);
p=localtime(&t);
n1=p->tm_sec;
n2=p->tm_min;
n3=p->tm_hour;
sound(1000);
delay(1000);
sound(1000);
nosound();
setfillstyle(1,0);
bar(200,150,290,200);
gotoxy(27,11);
printf("%d-%d-%d",1900+p->tm_year,1+p->tm_mon,p->tm_mday);
gotoxy(27,12);
printf("%d:%d:%d",p->tm_hour,p->tm_min,p->tm_sec);
h1=300+100*sin((n3+n2/60.0)*2*pi/12);
m1=300+150*sin(n2*2*pi/60);
s1=300+180*sin(n1*2*pi/60);
h2=240-100*cos((n3+n2/60.0)*2*pi/12);
m2=240-150*cos(n2*2*pi/60);
s2=240-180*cos(n1*2*pi/60);
setcolor(YELLOW);
line(300,240,h1,h2);
setcolor(RED);
line(300,240,m1,m2);
setcolor(BLUE);
line(300,240,s1,s2);
sleep(1);
setcolor(BLACK);
line(300,240,h1,h2);
line(300,240,m1,m2);
line(300,240,s1,s2);
}
getch();
closegraph();
return 0;
}
[解决办法]
"我知道应该用双缓冲，但要怎么写啊"
你这个还真是矛盾呀, 又知道, 又不知道?
双缓冲也就把要绘制的东西先绘制到内存中, 再一次绘制到屏幕上.
------解决方案--------------------
画图程序闪烁不一定是绘制速度的问题，所以双缓冲不一定能解决闪烁问题，很多闪烁问题可能是由于不断地背景切换造成的，可以从这方面找原因和解决方法
[解决办法]
仅供参考：
#include <graphics.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dos.h>
#include <conio.h>
#include <time.h>
#include <math.h>
time_t t;
char timestr1[30];//DDD MMM dd hh:mm:ss YYYY
char timestr2[30];//DDD MMM dd hh:mm:ss YYYY
char hhmmss[9];
int graphdriver,graphmode,page;
int i,xo,yo,r0,r1,r2,r3,r4,r5,r6,r7;
int x1,y1,x2,y2;
int hh,mm,ss;
double c,s;
int xasp,yasp;
void main() {
xo=60;yo=60;
r0=5; //轴
r1=20;//时针
r2=36;//分针
r3=45;//秒针
r4=50;//时刻度
r5=53;//分刻度
r6=55;//刻度外
r7=59;//表盘
graphdriver=VGA;
graphmode=VGAMED;
initgraph(&graphdriver,&graphmode,"D:\\BC\\BGI");
getaspectratio(&xasp, &yasp);
page=0;
timestr2[0]=0;
while (1) {
if (kbhit()) break;
time(&t);
strcpy(timestr1,ctime(&t));
if (strcmp(timestr1,timestr2)) {
strcpy(timestr2,timestr1);
hh=atoi(timestr2+11);
mm=atoi(timestr2+14);
ss=atoi(timestr2+17);
setvisualpage(page);
setactivepage(1-page);
cleardevice();
sprintf(hhmmss,"%02d:%02d:%02d",hh,mm,ss);
outtextxy(28,0,hhmmss);
pieslice(xo,yo,0,360,r0);
circle(xo,yo,r7);
for (i=0;i<60;i++) {
c=cos(i*6*3.14159265/180);
s=sin(i*6*3.14159265/180)*xasp/yasp;
if (0==(i%5)) {
x1=xo+r4*c;
y1=yo+r4*s;
} else {
x1=xo+r5*c;
y1=yo+r5*s;
}
x2=xo+r6*c;
y2=yo+r6*s;
line(x1,y1,x2,y2);
if (((hh%12)*5+mm/12+45)%60==i) {
x2=xo+r1*c;
y2=yo+r1*s;
setlinestyle(0,-1,3);
line(xo,yo,x2,y2);
setlinestyle(0,-1,1);
}
if ((mm+45)%60==i) {
x2=xo+r2*c;
y2=yo+r2*s;
setlinestyle(0,-1,3);
line(xo,yo,x2,y2);
setlinestyle(0,-1,1);
}
if ((ss+45)%60==i) {
x2=xo+r3*c;
y2=yo+r3*s;
line(xo,yo,x2,y2);
}
}
page=1-page;
}
delay(100);
}
getch();
closegraph();
}
