<div id="box">
  <div class="dinwei">
    <div class="pic">
      <img src="image/1.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/2.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/3.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/4.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/5.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/6.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/7.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/8.jpg">
    </div>
  </div>
  <div class="dinwei">
    <div class="pic">
      <img src="image/9.jpg">
    </div>
  </div>
</div>

<style type="text/css">
    *{
      margin: 0;
      padding: 0;
    }
    .dinwei{
      float: left;
    }
    .pic{
      padding: 5px;
      border: 1px solid #000000;
    }
    img{
      margin: 0;
      padding: 10px;
      width: 220px;
      height: auto;
    }
  </style>

<script type="text/javascript">
  window.onload=function(){
  var dinwei=document.getElementsByClassName("dinwei");
  var windwidth=document.documentElement.clientWidth||document.body.clientWidth;
  var dinwidth=getStyle(dinwei[0],"width");
  var num=Math.floor(windwidth/dinwidth);
  //計算一行幾張圖片
  //取出高度最小的列
  var heightList=[];
  for(var i=0;i<dinwei.length;i++){
    if(i<num){
      heightList[heightList.length]=getStyle(dinwei[i],"height");
    }else{
      var minHeight=getmin(heightList);
      var amin=minHeight.value;
      var index=minHeight.index;

      var temp=dinwei[i];
      temp.style.position="absolute";
      temp.style.top=amin+"px";
      temp.style.left=index*dinwidth+"px";
      heightList[index]=amin+getStyle(temp,"height");
    }
  }
  }
  function getmin(arr){
    var min=arr[0];[3,3,2,1,5,2]
    for(var i=1;i<arr.length;i++){
      if(arr[i]<min){
        min=arr[i];
      }
    }
    var index=0;
    for(var j=0;j<arr.length;j++){
      if(arr[j]==min){
        index=j;
        break;
      }
    }
    return {value:min,index:index}
  }
  function getStyle(obj, attr) {
    if (obj.currentStyle) {
      return parseFloat(obj.currentStyle[attr]);
    } else {
      return parseFloat(window.getComputedStyle(obj)[attr]);

    }
  }
</script>