JavaScript实现圆形菜单选择器

<head>
  <style>
    .mask{
      position: absolute;
      width: 502px;
      height: 252px;
      left:300px;
      top:350px;
      background: white;
      z-index: 999;
    }
    .con {
      width: 500px;
      height: 500px;
      overflow: hidden;
      position: absolute;
      border-radius: 100%;
      border: 1px solid black;
      user-select: none;
      cursor: pointer;
      left: 300px;
      top: 100px;
    }
 
    .con>div {
      position: absolute;
      width: 250px;
      height: 250px;
      /* border:1px solid black; */
      top: 0;
      left: 125px;
      text-align: center;
      font-size: 16px;
      transform-origin: bottom center;
    }
 
    .con1 {
      width: 400px;
      height: 400px;
      /* background: yellow; */
 
      overflow: hidden;
      position: absolute;
      border-radius: 100%;
      border: 1px solid black;
      user-select: none;
      cursor: pointer;
      left: 350px;
      top: 150px;
    }
 
    .con1>div {
      position: absolute;
      width: 200px;
      height: 200px;
      /* border:1px solid black; */
      top: 0;
      left: 100px;
      text-align: center;
      font-size: 16px;
      transform-origin: bottom center;
    }
  </style>
  <meta name="viewport"
    content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
</head>
 
<body>
  <div class="mask"></div>
  <div class="con">
  </div>
  <div class="con1">
  </div>
  <script>
    conRender();
    conRender1();
    function conRender() {
      var con = document.querySelector(".con");
      var len = 16;
      var deg = 360 / len;
      for (var i = 0; i < len; i++) {
        var dom = document.createElement("div");
        dom.style.transform = "rotate(-" + i * deg + "deg)";
        dom.innerHTML = "财务管理" + i;
        dom.setAttribute("index", i)
        con.appendChild(dom)
      }
      var mouseDown = false;
      var startX = 0;
      var startY = 0;
      var endX = 0;
      var endY = 0;
      var rotate = 0;
      con.addEventListener("mousedown", function (e) {
        mouseDown = true;
        startX = e.pageX;
        startY = e.pageY;
      }, false);
      con.addEventListener("mousemove", function (e) {
        if (mouseDown) {
          endX = e.pageX;
          endY = e.pageY;
          var distance = Math.sqrt(Math.pow((endX - startX), 2) + Math.pow((endY - startY), 2))
          if (endX - startX < 0 || endY - startY < 0) {
            distance = -distance
          }
          rotate += distance
          con.style.transform = "rotate(" + (rotate / 4) + "deg)";
          startX = e.pageX;
          startY = e.pageY;
          var index = Math.round((rotate / 4) / deg);
          var cons = document.querySelectorAll(".con>div")
          for (var i = 0, len = cons.length; i < len; i++) {
            cons[i].style.color = "black"
          }
          document.querySelector("div[index=\"" + index % len + "\"]").style.color = "red"
          document.querySelector(".con1").style.transform = "rotate(" + (rotate) + "deg)";
        }
      }, false);
      document.addEventListener("mouseup", function (e) { mouseDown = false; }, false);
 
    }
    function conRender1() {
      var con = document.querySelector(".con1");
      var len = 13;
      var deg = 360 / len;
      for (var i = 0; i < len; i++) {
        var dom = document.createElement("div");
        dom.style.transform = "rotate(-" + i * deg + "deg)";
        dom.innerHTML = "财务管理" + i;
        dom.setAttribute("index1", i)
        con.appendChild(dom)
      }
      var mouseDown = false;
      var startX = 0;
      var startY = 0;
      var endX = 0;
      var endY = 0;
      var rotate = 0;
      con.addEventListener("mousedown", function (e) {
        mouseDown = true;
        startX = e.pageX;
        startY = e.pageY;
      }, false);
      con.addEventListener("mousemove", function (e) {
        if (mouseDown) {
          endX = e.pageX;
          endY = e.pageY;
          var distance = Math.sqrt(Math.pow((endX - startX), 2) + Math.pow((endY - startY), 2))
          if (endX - startX < 0 || endY - startY < 0) {
            distance = -distance
          }
          rotate += distance
          con.style.transform = "rotate(" + (rotate / 4) + "deg)";
          startX = e.pageX;
          startY = e.pageY;
          var index = Math.round((rotate / 4) / deg);
          var cons = document.querySelectorAll(".con1>div")
          for (var i = 0, len = cons.length; i < len; i++) {
            cons[i].style.color = "black"
          }
          document.querySelector("div[index1=\"" + index % len + "\"]").style.color = "red"
        }
      }, false);
      document.addEventListener("mouseup", function (e) { mouseDown = false; }, false);
 
    }
  </script>
</body>
 
</html>