js实现拖拽改变dom元素大小

谁借莪１个温暖的怀抱￠ 2021-11-09 17:32 573阅读 0赞

<!DOCTYPE html>
    <html>
    <head>
        <title></title>
        <style>
        #panel{
          position: absolute;
          width: 200px;height: 200px;
          background: green;
        }
        #dragIcon{
          position: absolute;bottom: 0;right: 0;
          width: 20px;height: 20px;
          background: yellow;
        }
    </style>
    </head>
    <body>
    <div id="panel">
      <div id="dragIcon"></div>
    </div>
    
    <script>
      window.onload = function () {
        // 1. 获取两个大小div
        var oPanel = document.getElementById('panel');
        var oDragIcon = document.getElementById('dragIcon');
        // 定义4个变量
        var disX = 0;//鼠标按下时光标的X值
        var disY = 0;//鼠标按下时光标的Y值
        var disW = 0; //拖拽前div的宽
        var disH = 0; // 拖拽前div的高
        //3. 给小div加点击事件
        oDragIcon.onmousedown = function (ev) {
          var ev = ev || window.event;
          disX = ev.clientX; // 获取鼠标按下时光标x的值
          disY = ev.clientY; // 获取鼠标按下时光标Y的值
          disW = oPanel.offsetWidth; // 获取拖拽前div的宽
          disH = oPanel.offsetHeight; // 获取拖拽前div的高
          document.onmousemove = function (ev) {
            var ev = ev || window.event;
            //拖拽时为了对宽和高 限制一下范围，定义两个变量
            var W = ev.clientX - disX + disW;
            var H = ev.clientY - disY + disH;
            if(W<100){
              W = 100;
            }
            if(W>800){
              W =800;
            }
            if(H<100){
              H = 100;
            }
            if(H>500){
              H = 500;
            }
            oPanel.style.width =W +'px';// 拖拽后物体的宽
            oPanel.style.height = H +'px';// 拖拽后物体的高
          }
          document.onmouseup = function () {
            document.onmousemove = null;
            document.onmouseup = null;
          }
        }
      }
    </script>
    </body>
    </html>