一、检测按键是否按下

#include"reg52.h"
typedef unsigned char u8;
typedef unsigned int u16;
sbit led=P2^0;
sbit ke=P3^1;void delay(u16 i)
{while(i--);
}void anjian()
{if(ke==0)//判断按键是否被按下{delay(1000);//消抖if(ke==0)//消抖之后再次判断是否被按下 ?led=~led;//点亮led灯，led灯默认高电'平while(!ke);//判断是否断开} 
}void main()
{while(1){anjian();}
}