<div id="dragContainer"><!-- 容器初始背景 -->
  <div id="dragBg"></div><!-- 绿色背景 -->
  <div id="dragText"></div><!-- 滑动容器文本 -->
  <div id="dragHandler" class="dragHandlerBg"></div>
</div> <!--    滑块         滑块初始背景 -->

/* 滑动控件容器,灰色背景 */
#dragContainer {
  position: relative;
  display: inline-block;
  background: #e8e8e8;
  width: 300px;
  height: 33px;
  border: 2px solid #e8e8e8;
}
/* 滑块左边部分,绿色背景 */
#dragBg {
  position: absolute;
  background-color: #7ac23c;
  width: 0px;
  height: 100%;
}
/* 滑动验证容器文本 */
#dragText {
  position: absolute;
  width: 100%;
  height: 100%;
  /* 文字水平居中 */
  text-align: center;
  /* 文字垂直居中,这里不能用百分比,因为百分比是相对原始line-height的,而非div高度 */
  line-height: 33px;
  /* 文本不允许选中 */
  user-select: none;
  -webkit-user-select: none;
}
/* 滑块 */
#dragHandler {
  position: absolute;
  width: 40px;
  height: 100%;
  cursor: move;
}
/* 滑块初始背景 */
.dragHandlerBg {
  background: #fff no-repeat center url("data:image/png;base64,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");
}
/* 验证成功时的滑块背景 有√*/
.dragHandlerOkBg {
  background: #fff no-repeat center url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAA3hpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADw/eHBhY2tldCBiZWdpbj0i77u/IiBpZD0iVzVNME1wQ2VoaUh6cmVTek5UY3prYzlkIj8+IDx4OnhtcG1ldGEgeG1sbnM6eD0iYWRvYmU6bnM6bWV0YS8iIHg6eG1wdGs9IkFkb2JlIFhNUCBDb3JlIDUuNS1jMDIxIDc5LjE1NTc3MiwgMjAxNC8wMS8xMy0xOTo0NDowMCAgICAgICAgIj4gPHJkZjpSREYgeG1sbnM6cmRmPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5LzAyLzIyLXJkZi1zeW50YXgtbnMjIj4gPHJkZjpEZXNjcmlwdGlvbiByZGY6YWJvdXQ9IiIgeG1sbnM6eG1wTU09Imh0dHA6Ly9ucy5hZG9iZS5jb20veGFwLzEuMC9tbS8iIHhtbG5zOnN0UmVmPSJodHRwOi8vbnMuYWRvYmUuY29tL3hhcC8xLjAvc1R5cGUvUmVzb3VyY2VSZWYjIiB4bWxuczp4bXA9Imh0dHA6Ly9ucy5hZG9iZS5jb20veGFwLzEuMC8iIHhtcE1NOk9yaWdpbmFsRG9jdW1lbnRJRD0ieG1wLmRpZDo0ZDhlNWY5My05NmI0LTRlNWQtOGFjYi03ZTY4OGYyMTU2ZTYiIHhtcE1NOkRvY3VtZW50SUQ9InhtcC5kaWQ6NDlBRDI3NjVGMkQ2MTFFNEI5NDBCMjQ2M0ExMDQ1OUYiIHhtcE1NOkluc3RhbmNlSUQ9InhtcC5paWQ6NDlBRDI3NjRGMkQ2MTFFNEI5NDBCMjQ2M0ExMDQ1OUYiIHhtcDpDcmVhdG9yVG9vbD0iQWRvYmUgUGhvdG9zaG9wIENDIDIwMTQgKE1hY2ludG9zaCkiPiA8eG1wTU06RGVyaXZlZEZyb20gc3RSZWY6aW5zdGFuY2VJRD0ieG1wLmlpZDphNWEzMWNhMC1hYmViLTQxNWEtYTEwZS04Y2U5NzRlN2Q4YTEiIHN0UmVmOmRvY3VtZW50SUQ9InhtcC5kaWQ6NGQ4ZTVmOTMtOTZiNC00ZTVkLThhY2ItN2U2ODhmMjE1NmU2Ii8+IDwvcmRmOkRlc2NyaXB0aW9uPiA8L3JkZjpSREY+IDwveDp4bXBtZXRhPiA8P3hwYWNrZXQgZW5kPSJyIj8+k+sHwwAAASZJREFUeNpi/P//PwMyKD8uZw+kUoDYEYgloMIvgHg/EM/ptHx0EFk9I8wAoEZ+IDUPiIMY8IN1QJwENOgj3ACo5gNAbMBAHLgAxA4gQ5igAnNJ0MwAVTsX7IKyY7L2UNuJAf+AmAmJ78AEDTBiwGYg5gbifCSxFCZoaBMCy4A4GOjnH0D6DpK4IxNSVIHAfSDOAeLraJrjgJp/AwPbHMhejiQnwYRmUzNQ4VQgDQqXK0ia/0I17wJiPmQNTNBEAgMlQIWiQA2vgWw7QppBekGxsAjIiEUSBNnsBDWEAY9mEFgMMgBk00E0iZtA7AHEctDQ58MRuA6wlLgGFMoMpIG1QFeGwAIxGZo8GUhIysmwQGSAZgwHaEZhICIzOaBkJkqyM0CAAQDGx279Jf50AAAAAABJRU5ErkJggg==");
}

//加载（事件会在页面加载完成后触发）
window.onload = function() {
  //获取滑动控件容器,灰色背景
  var dragContainer = document.getElementById("dragContainer");
  //获取滑块左边部分,绿色背景
  var dragBg = document.getElementById("dragBg");
  //获取滑动验证容器文本
  var dragText = document.getElementById("dragText");
  //获取滑块
  var dragHandler = document.getElementById("dragHandler");

  //滑块的最大偏移量                 =     滑动验证容器文本长度                  -      滑块长度
  var maxHandlerOffset = dragContainer.clientWidth - dragHandler.clientWidth;
  //是否验证成功的标记
  var isVertifySucc = false;

  initDrag();

  function initDrag() {
    //在滑动验证容器文本写入“拖动滑块验证”
    dragText.textContent = "拖动滑块验证";
    //给滑块添加鼠标按下监听
    dragHandler.addEventListener("mousedown", onDragHandlerMouseDown);
  }

  //选中滑块
  function onDragHandlerMouseDown() {
    //鼠标移动监听
    document.addEventListener("mousemove", onDragHandlerMouseMove);
    //鼠标松开监听
    document.addEventListener("mouseup",  onDragHandlerMouseUp);
  }

  //滑块移动
  function onDragHandlerMouseMove() {
    /*
                html元素不存在width属性,只有clientWidth
                offsetX是相对当前元素的,clientX和pageX是相对其父元素的
                */
    //滑块移动量
    var left = event.clientX - dragHandler.clientWidth / 2;
    //
    if(left < 0) {
      left = 0;
      //如果滑块移动量   > 滑块的最大偏移量 ，则调用验证成功函数
    } else if(left > maxHandlerOffset) {
      left = maxHandlerOffset;
      verifySucc();
    }
    //滑块移动量
    dragHandler.style.left = left + "px";
    //绿色背景的长度
    dragBg.style.width = dragHandler.style.left;
  }

  //松开滑块函数
  function onDragHandlerMouseUp() {
    //移除鼠标移动监听
    document.removeEventListener("mousemove", onDragHandlerMouseMove);
    //移除鼠标松开监听
    document.removeEventListener("mouseup", onDragHandlerMouseUp);
    //初始化滑块移动量
    dragHandler.style.left = 0;
    //初始化绿色背景
    dragBg.style.width = 0;
  }

  //验证成功
  function verifySucc() {
    //成功标记，不可回弹
    isVertifySucc = false;
    //容器文本的文字改为白色“验证通过”字体
    dragText.textContent = "验证通过";
    dragText.style.color = "white";
    //验证通过的滑块背景
    dragHandler.setAttribute("class", "dragHandlerOkBg");
    //移除鼠标按下监听
    dragHandler.removeEventListener("mousedown", onDragHandlerMouseDown);
    //移除 鼠标移动监听
    document.removeEventListener("mousemove", onDragHandlerMouseMove);
    //移除鼠标松开监听
    document.removeEventListener("mouseup", onDragHandlerMouseUp);
    // 匹配成功以后写入你要跳转的页面
    window.open("https://mankeung.github.io/docs/mk-data");
  };
}