js滑动进度条效果

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  <!DOCTYPE html>
  <html>
  <head>
      <meta charset="utf-8" />
      <title>js滑动进度条效果</title>
      <style>
        *{margin:0;padding:0;user-select:none;}
        .progress-bar{position:relative;height:10px;width:400px;margin:200px auto;background:#ebeef5;border-radius:10px;}
        .progress-bar .pro-bar{position:absolute;left:0;height:10px;width:10px;background:#409eff;}
        .progress-bar .min-num{position:absolute;left:-20px;top:-5px;}
        .progress-bar .max-num{position:absolute;right:-40px;top:-5px;}
        .progress-bar .block {position:absolute;height:30px;width:10px;background:#ccc;top:-10px;border-radius:10px;}
        .progress-bar .block div{position:absolute;display:none;left:-20px;top:-45px;width:50px;height:30px;text-align:center;line-height:30px;background:#ccc;border-radius:20px;}
        .progress-bar .block:hover div{display:block;font-size:10%;color:#fff;background:#409eff;}
      </style>
  </head>
  <body>
    <div class="progress-bar">
      <span class="min-num">0</span>
      <span class="max-num">100</span>
      <div class="pro-bar"></div>
      <div class="block">
        <div>0</div>
      </div>
    </div>
  </body>
  <script>
    (function(){
      let moveBlock = document.querySelector('.block');
      let proBar = document.querySelector('.pro-bar');
      let flag = false;
      let startX = null;
      let moveMax = (400 - 10); // 背景条宽度减去滑块的宽度
      moveBlock.onmousedown = function(e){
        startX = e.pageX;
        moveBlock.style.left ? moveBlock.style.left : moveBlock.style.left = '0px';
        let startLeft = parseInt(moveBlock.style.left);
        document.onmousemove = function(e){
          let moveX = (e.pageX - startX) > 0 ? true : false;
          let moveSection = startLeft + (e.pageX - startX);
          // 限定移动范围
          if (moveSection >= 0 && moveSection <= moveMax) {
            let percent = ((startLeft + (e.pageX - startX)) / moveMax).toFixed(4) * 100;
            percent.toString().length > 5 ? percent = percent.toString().subStr(0, 5) : percent = percent.toString();
            moveBlock.style.left = startLeft + (e.pageX - startX) + 'px';
            proBar.style.width = moveBlock.style.left;
            moveBlock.querySelector('div').innerText = percent + '%';
          }
        };
      };
      // 鼠标松开移除事件
      moveBlock.onmouseup = function(){
        document.onmousemove = null;
      };
    })();
  </script>
  </html>