原生js螺旋运动

window.onload=function(){

var oSpiral=document.getElementById('spiral');

var oUl=oSpiral.getElementsByTagName('ul')[0];

var aLi=oUl.getElementsByTagName('li');

var size=6;

var len=size*size;

var eachSize=50;

var col=0;

var row=0;

var min=0;

var max=size-1;

var arr=[];

var bgArr=[];

oUl.style.width=size*(eachSize+1)+'px';

oUl.style.height=size*(eachSize+1)+'px';

for(var i=0;i<len;i++){

var oLi=document.createElement('li');

oLi.style.width=eachSize+'px';

oLi.style.height=eachSize+'px';

oUl.appendChild(oLi);

}

for(var j=0;j<len;j++){

//aLi[ row * size + col ].innerHTML = j;

arr.push(aLi[row*size+col]);

if(row === min && col < max){

col++;

}else if(col === max && row < max){

row++;

}else if(row ===max && col > min){

col--;

}else if(col === min && row > min){

row--;

}if(row-1===min && col===min){

min++;

max--;

}

}

for(var i=0;i<len;i++){

if(i%4===0){

var n=Math.floor(Math.random()*10);

var bgImg='url(../images/'+n+'.jpg)';

arr[i].style.backgroundImage=bgImg;

bgArr.push([i,bgImg]);

}

}

move();

setInterval(move,1000);

function move(){

for(var i=0;i<aLi.length;i++){

aLi[i].style.backgroundImage='';

aLi[i].className='';

}

for(var i=0;i<bgArr.length;i++){

bgArr[i][0]++;

if(arr[bgArr[i][0]]){

arr[bgArr[i][0]].style.backgroundImage=bgArr[i][1];

arr[bgArr[i][0]].className='active';

arr[bgArr[i][0]].style.animationDelay = -Math.random()*1 + 's';

arr[bgArr[i][0]].style.webkitAnimationDelay = -Math.random()*1 + 's';

}else{

bgArr.pop();

var n=Math.floor(Math.random()*10);

var bgImg='url(../images/'+n+'.jpg)';

bgArr.unshift([0,bgImg]);

}





}

}

}