howto 在线编辑器 | howto代码测试

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>/*容器必须相对定位：*/
.custom-select {
  position: relative;
  font-family: Arial;
}

.custom-select select {
  display: none; /*隐藏原来的SELECT元素：*/
}

.select-selected {
  background-color: DodgerBlue;
}

/*在 select 元素中设置箭头样式：*/
.select-selected:after {
  position: absolute;
  content: "";
  top: 14px;
  right: 10px;
  width: 0;
  height: 0;
  border: 6px solid transparent;
  border-color: #fff transparent transparent transparent;
}

/*当选择框打开（活动）时，将箭头指向上方：*/
.select-selected.select-arrow-active:after {
  border-color: transparent transparent #fff transparent;
  top: 7px;
}

/*设置项目（选项）的样式，包括选中的项目：*/
.select-items div,.select-selected {
  color: #ffffff;
  padding: 8px 16px;
  border: 1px solid transparent;
  border-color: transparent transparent rgba(0, 0, 0, 0.1) transparent;
  cursor: pointer;
  user-select: none;
}

/*style items (options):*/
.select-items {
  position: absolute;
  background-color: DodgerBlue;
  top: 100%;
  left: 0;
  right: 0;
  z-index: 99;
}

/*当选择框关闭时隐藏项目：*/
.select-hide {
  display: none;
}

.select-items div:hover, .same-as-selected {
  background-color: rgba(0, 0, 0, 0.1);
}
</style>
</head>

<body>

<h2>自定义选择</h2>

<div class="custom-select" style="width:200px;">
  <select>
    <option value="0">选择汽车：</option>
    <option value="1">Audi</option>
    <option value="2">BMW</option>
    <option value="3">Citroen</option>
    <option value="4">Ford</option>
    <option value="5">Honda</option>
    <option value="6">Jaguar</option>
    <option value="7">Land Rover</option>
    <option value="8">Mercedes</option>
    <option value="9">Mini</option>
    <option value="10">Nissan</option>
    <option value="11">Toyota</option>
    <option value="12">Volvo</option>
  </select>
</div>

<script>
var x, i, j, l, ll, selElmnt, a, b, c;
/* 查找具有类 "custom-select" 的任何元素：*/
x = document.getElementsByClassName("custom-select");
l = x.length;
for (i = 0; i < l; i++) {
  selElmnt = x[i].getElementsByTagName("select")[0];
  ll = selElmnt.length;
  /* 为每个元素创建一个新的 DIV 作为被选项：*/
  a = document.createElement("DIV");
  a.setAttribute("class", "select-selected");
  a.innerHTML = selElmnt.options[selElmnt.selectedIndex].innerHTML;
  x[i].appendChild(a);
  /*为每个元素创建一个包含选项列表的新 DIV:*/
  b = document.createElement("DIV");
  b.setAttribute("class", "select-items select-hide");
  for (j = 1; j < ll; j++) {
    /*对于原始选择元素中的每个选项，
     创建一个新的 DIV 作为选项：*/
    c = document.createElement("DIV");
    c.innerHTML = selElmnt.options[j].innerHTML;
    c.addEventListener("click", function(e) {
        /*当一个项目被点击时，更新原来的选择框，
         以及被选中的项目：*/
        var y, i, k, s, h, sl, yl;
        s = this.parentNode.parentNode.getElementsByTagName("select")[0];
        sl = s.length;
        h = this.parentNode.previousSibling;
        for (i = 0; i < sl; i++) {
          if (s.options[i].innerHTML == this.innerHTML) {
            s.selectedIndex = i;
            h.innerHTML = this.innerHTML;
            y = this.parentNode.getElementsByClassName("same-as-selected");
            yl = y.length;
            for (k = 0; k < yl; k++) {
              y[k].removeAttribute("class");
            }
            this.setAttribute("class", "same-as-selected");
            break;
          }
        }
        h.click();
    });
    b.appendChild(c);
  }
  x[i].appendChild(b);
  a.addEventListener("click", function(e) {
      /*当选择框被点击时，关闭任何其他选择框，
      并打开/关闭当前选择框：*/
      e.stopPropagation();
      closeAllSelect(this);
      this.nextSibling.classList.toggle("select-hide");
      this.classList.toggle("select-arrow-active");
    });
}
function closeAllSelect(elmnt) {
  /* 关闭文档中所有选择框的函数，
   除了当前选择框：*/
  var x, y, i, xl, yl, arrNo = [];
  x = document.getElementsByClassName("select-items");
  y = document.getElementsByClassName("select-selected");
  xl = x.length;
  yl = y.length;
  for (i = 0; i < yl; i++) {
    if (elmnt == y[i]) {
      arrNo.push(i)
    } else {
      y[i].classList.remove("select-arrow-active");
    }
  }
  for (i = 0; i < xl; i++) {
    if (arrNo.indexOf(i)) {
      x[i].classList.add("select-hide");
    }
  }
}
/*如果用户点击了选择框外的任意位置，
则关闭所有选择框：*/
document.addEventListener("click", closeAllSelect);
</script>

</body>
</html>