键盘问题

只看该作者 · 2010-10-29 10:28

#include<reg52.h>
  #define uchar unsigned char
  #define uint unsigned int
  uchar code dula[]={0x3F,  //"0"
            0x06,  //"1"
            0x5B,  //"2"
            0x4F,  //"3"
            0x66,  //"4"
            0x6D,  //"5"
            0x7D,  //"6"
            0x07,  //"7"
            0x7F,  //"8"
            0x6F,  //"9"
            0x77,  //"A"
            0x7C,  //"B"
            0x39,  //"C"
            0x5E,  //"D"
            0x79,  //"E"
            0x71,  };
void  delay(uint z)
  {
  uint x,y;
   for(x=100;x>0;x--)
for(y=z;y>0;y--);

  }
keyboard()
  {
uchar rcode,ccode;
P0=0xf0;
if((P0&0xf0)!=0xf0)
{ delay(4);
  if((P0&0xf0)!=0xf0)
  {
rcode=0xfe;
while((rcode&0x10)!=0)
{
P0=rcode;
   if((P0&0xf0)!=0xf0)
   {

   ccode=(P0&0xf0)|0x0f;
   do{;}while((P0&0xf0)!=0xf0);
   delay(4);
   while((P0&0xf0)!=0xf0);

   return((~rcode)+(~ccode));
   }
   else rcode=(rcode<<1)|0x01;


}
  }
  }
   return 0;
  }
  void disp(k)
{
P2=dula[k];
P1=0xff;
delay(1);
}
void  display(k)
  {
switch(k)
{
  case 0x11:disp(0);break;
  case 0x21:disp(1);break;
  case 0x41:disp(2);break;
  case 0x81:disp(3);break;
  case 0x12:disp(4);break;
  case 0x22:disp(5);break;
  case 0x42:disp(6);break;
  case 0x82:disp(7);break;
  case 0x14:disp(8);break;
  case 0x24:disp(9);break;
  case 0x44:disp(10);break;
  case 0x84:disp(11);break;
  case 0x18:disp(12);break;
  case 0x28:disp(13);break;
  case 0x48:disp(14);break;
  case 0x88:disp(15);break;
  default:
  break;

}
  }

void  main()
  {
   while(1)
{
   uchar key;
key=keyboard();
display(key);

}

其中main()函数中，我若这样改
void main（）
{
while(1)
{
display(keyboard());
}
}
这样就不行了，请大家看看这是为什么啊

  }