用三个独立按键实现按下第一个时计时停止，按下第二个时计时开始，按下第三个时计数值清零从头开始，秒表设计！！！！

#include
#include
#define uchar unsigned char 
#define uint unsigned int
sbit dula=P2^6;
sbit wela=P2^7;
sbit key1=P3^5;
sbit key2=P3^4;
sbit key3=P3^3;
sbit key4=P3^2;
uchar code tab[]={
0xc0,0xf9,0xa4,0xb0,
0x99,0x92,0x82,0xf8,
0x80,0x90,0x88,0x83,
0xc6,0xa1,0x86,0x8e};
uchar temp,bai,shi,ge,aa,flag,flag1,t0,t1;
uint shu;
void display(uchar bai,uchar shi,uchar ge);
void init();
void delay(uint z);

void main()
{
	init();
	while(1)
		{
			 display(bai,shi,ge);
			 	if(key1==0)
				{
				   delay(5);
				   if(key1==0)
				   TR0=0;
				   
					
				 }
				 if(key2==0)
				   {
				   		TR0=1;
						display(bai,shi,ge);

				   }
				  if(key3==0)
				  {
				  	
				  	shu=0;
					display(bai,shi,ge);
					
				  }
	}
}
		

	void init()
	{
		shu=0;
		TMOD=0x01;
		TH0=(65536-10000)/256;
		TL0=(65536-10000)%256;
		EA=1;
		ET0=1;
		TR0=1;

	}
		
			void time0() interrupt 1
			{
				TH0=(65536-10000)/256;
				TL0=(65536-10000)%256;
				t0++; 
				if(t0==1)
				{
					t0=0;
					bai=shu/100;
					shi=shu%100/10;
					ge=shu%10;
					shu++;
					if(shu==1000)
					shu=0;
				}
			

			}
				void display(uchar bai,uchar shi,uchar ge)
				{
					wela=1;
					P2=0xfe;
					wela=0;
					dula=1;
					P0=tab[bai];
					dula=0;
					delay(5);

					wela=1;
					P2=0xfd;
					wela=0;
					dula=1;
					P0=tab[shi];
					dula=0;
					delay(5);

					wela=1;
					P2=0xfb;
					wela=0;
					dula=1;
					P0=tab[ge];
					dula=0;
					delay(5);

				}
					void delay(uint z)
					{
						uint x,y;
						for(x=0;x

这个主要是用if语句控制的！废话不多说了没遇到啥问题，还是自己有些马虎了