DIV CSS 佈局教程網

本文實例為大家講解了JS實現拖拽圖片效果的詳細代碼，分享給大家供大家參考，具體內容如下

javascript event 對象的clientX,offsetX,screenX,pageX的區別：

用html5的drag來實現拖拽有兼容性問題，使用拖拽插件代碼又很多，而這個拖拽demo代碼少，並且兼容所有浏覽器，很值得在項目中使用，

css樣式如下：

  #div1{ 
    width: 100px; height: 100px; 
    background-color: #4D4D4D; 
    position: absolute; cursor: pointer; 
    -webkit-box-shadow: 3px 3px 0px 3px #C7C7C7; 
    box-shadow: 3px 3px 3px 0px #C7C7C7; 
  }
  #parent{ 
    width: 500px; height: 500px; 
    border: 1px solid #CDCDCD; 
    position: relative; margin: 0 auto;  //父級元素設置為：
    background-color: #F4F4F4; 
  }
  .postText{
    width: 500px; height: 30px;margin: 0 auto; background-color: #F4F4F4;
  }
  .postText span{ 
   padding:0px 10px;
  }

html代碼如下：

<div id="parent">
  <div id="div1" onmousemove="posMove(this.id)"></div>
</div>
<div class="postText">
  移動的距離Top：<span id="posTop"></span>Left:<span id="posLeft"></span>
</div>

js代碼及注釋如下

function posMove(getdivid) {
    var oDiv = document.getElementById(getdivid);
    var oParent = document.getElementById('parent');
    var sent = {
      l: 10, //設置div在父元素的活動范圍，10相當於給父div設置padding-left：10;
      r: oParent.offsetWidth - oDiv.offsetWidth, // offsetWidth:當前對象的寬度， offsetWidth = width+padding+border
      t: 10,
      b: oParent.offsetHeight - oDiv.offsetHeight,
      n: 10
    }
    drag(oDiv, sent); 
  }
  
  /**
   *
   * @param obj:被拖動的div
   * @param sent :設置div在容器中可以被拖動的區域
   */
  function drag(obj,sent){

    var dmW = document.documentElement.clientWidth || document.body.clientWidth;
    var dmH = document.documentElement.clientHeight || document.body.clientHeight;

    var sent = sent || {};
    var l = sent.l || 0;
    var r = sent.r || dmW - obj.offsetWidth;
    var t = sent.t || 0;
    var b = sent.b || dmH - obj.offsetHeight;
    var n = sent.n || 10;

    obj.onmousedown = function (ev){
      var oEvent = ev || event;
      var sentX = oEvent.clientX - obj.offsetLeft;
      var sentY = oEvent.clientY - obj.offsetTop;

      document.onmousemove = function (ev){
        var oEvent = ev || event;

        var slideLeft = oEvent.clientX - sentX;
        var slideTop = oEvent.clientY - sentY;

        if(slideLeft <= l){
          slideLeft = l;
        }
        if(slideLeft >= r){
          slideLeft = r;
        }
        if(slideTop <= t){
          slideTop = t;
        }
        if(slideTop >= b){
          slideTop = b;
        }

        obj.style.left = slideLeft + 'px';
        obj.style.top = slideTop + 'px';

        document.getElementById('posTop').innerHTML = slideTop;
        document.getElementById('posLeft').innerHTML = slideLeft;

      };
      document.onmouseup = function (){
        document.onmousemove = null;
        document.onmouseup = null;
      }

      return false;
    }
  }  

以上就是關於js拖拽效果的實現代碼，希望對大家的學習有所幫助。