如何在51单片机矩阵键盘里按一个键可实现数码管动态显示而不是一个值

#include
#define uchar unsigned char;
uchar distab[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x00};  //0到f
void delay(unsigned int a)
{
	unsigned int i,j;
	for(i=0;i		for(j=0;j<120;j++);
}
uchar kbscan(void)
{
	unsigned char sccode,recode;
	P1=0x0f;  //发0扫描,列线输入
	if ((P2 & 0x0f) != 0x0f)  //有键按下
	{
		delay(20);   //延时去抖动
		if ((P1&0x0f)!= 0x0f)
		{
			sccode = 0xef;    //逐行扫描初值
			while((sccode&0x01)!=0)
			{
			    P1=sccode;
				if((P1&0x0f)!=0x0f)
				{
				    recode=(P1&0x0f)|0xf0;
					while((P1&0x0f)!=0x0f);//等待键抬起
					return((~sccode)+(~recode));
				 }
		        else
				sccode=(sccode<<1)|0x01;
			}
		}
	}
	return 0;  //无键按下，返回0
}

uchar getkey(void)
{
	unsigned char key,keyval=0xff;
	key=kbscan();
		switch(key)
		{
		case 0x11:keyval=1;break;
		case 0x12:keyval=2;break;
		case 0x14:keyval=3;break;
		case 0x18:keyval=10;break;	//+
		case 0x21:keyval=4;break;
		case 0x22:keyval=5;break;
		case 0x24:keyval=6;break;
		case 0x28:keyval=11;break;	//-
		case 0x41:keyval=7;break;
		case 0x42:keyval=8;break;
		case 0x44:keyval=9;break;
		case 0x48:keyval=12;break;	//清除
		case 0x81:keyval=13;break;
		case 0x82:keyval=0;break;
		case 0x84:keyval=14;break;	//小数点
		case 0x88:keyval=15;break;	//确认
		default:keyval=16;break;
		}
		return(keyval);
}
main()
{
uchar keyin;
		while(1)
		{
		keyin=getkey();
		P0=distab[keyin];
		}
}