这是源程序：
#include "reg52.h"
unsigned char code table[]={0x3f,0x06,0x5b,0x4f,0x66};
unsigned char keyscan()
{unsigned char keyv,temp;
keyv=0;
P2=0xff;
temp=P2;
if(~(P2&temp))
{switch(temp)
{case 0xfe:
  keyv=1;break;
case 0xfd:
  keyv=2;break;
case 0xfb:
  keyv=3;break;
case 0xf7:
  keyv=4;break;
default:
  keyv=0;break;
}
}
return keyv;
}
void main ()
{
unsigned char ledshow;
while(1)
{ledshow=keyscan();
P1=table[ledshow];
}
}

本人初学者，希望各位指点下，在线等待中......

这是仿真电路图