javascript - 无法使用 AJAX 获取选择值

Question

我有带有一些值的选择框并使用 AJAX 将数据发送到 php 并在 <div> 中显示这些数据，这是我的代码，我不知道为什么它不起作用。

当我使用按钮从中获取值(value)时，它是有效的。我已经尝试了多个教程并提出了很多关于 AJAX 和选择框的问题。

我尝试制作函数并在内部选择使用 onchange 调用它

product.php

<div id="input-option232">
<div class="checkbox">


<div class="custom-select" style="width: 200px">
<form method="get" name="rate">

<select name="rate2" id="rate2">

<option value="0">Broj Rata:</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
</select>
</form>
</div>

</div>
<div id="ratice"></div> // I WANT TO DISPLAY HERE
</div>

aj-select.js

$("#rate2").on('change', function() {
        var level = $('#rate2').val();
        if(level){
            $.ajax ({
                type: 'GET',
                url: 'rate.php',
                data: 'rate='+level,
                success : function(data) {
                    $('#ratice').html(data);
                }
            });
        }
    });

rate.php

<?php
if(isset($_GET['rate'])){
    echo $rate = $_GET['rate'];
}

?>

select.js

var x, i, j, selElmnt, a, b, c;
/*look for any elements with the class "custom-select":*/
x = document.getElementsByClassName("custom-select");
for (i = 0; i < x.length; i++) {
  selElmnt = x[i].getElementsByTagName("select")[0];
  /*for each element, create a new DIV that will act as the selected item:*/
  a = document.createElement("DIV");
  a.setAttribute("class", "select-selected");
  a.innerHTML = selElmnt.options[selElmnt.selectedIndex].innerHTML;
  x[i].appendChild(a);
  /*for each element, create a new DIV that will contain the option list:*/
  b = document.createElement("DIV");
  b.setAttribute("class", "select-items select-hide");
  for (j = 0; j < selElmnt.length; j++) {
    /*for each option in the original select element,
    create a new DIV that will act as an option item:*/
    c = document.createElement("DIV");
    c.innerHTML = selElmnt.options[j].innerHTML;
    c.addEventListener("click", function(e) {
        /*when an item is clicked, update the original select box,
        and the selected item:*/
        var y, i, k, s, h;
        s = this.parentNode.parentNode.getElementsByTagName("select")[0];
        h = this.parentNode.previousSibling;
        for (i = 0; i < s.length; i++) {
          if (s.options[i].innerHTML === this.innerHTML) {
            s.selectedIndex = i;
            h.innerHTML = this.innerHTML;
            y = this.parentNode.getElementsByClassName("same-as-selected");
            for (k = 0; k < y.length; 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) {
      /*when the select box is clicked, close any other select boxes,
      and open/close the current select box:*/
      e.stopPropagation();
      closeAllSelect(this);
      this.nextSibling.classList.toggle("select-hide");
      this.classList.toggle("select-arrow-active");
    });
}
function closeAllSelect(elmnt) {
  /*a function that will close all select boxes in the document,
  except the current select box:*/
  var x, y, i, arrNo = [];
  x = document.getElementsByClassName("select-items");
  y = document.getElementsByClassName("select-selected");
  for (i = 0; i < y.length; i++) {
    if (elmnt === y[i]) {
      arrNo.push(i);
    } else {
      y[i].classList.remove("select-arrow-active");
    }
  }
  for (i = 0; i < x.length; i++) {
    if (arrNo.indexOf(i)) {
      x[i].classList.add("select-hide");
    }
  }
}
/*if the user clicks anywhere outside the select box,
then close all select boxes:*/
document.addEventListener("click", closeAllSelect);

CSS

<style type="text/css">
         body{font-family:'Roboto', sans-serif}
        .custom-select {
  position: relative;
  font-family: Arial;
}
.custom-select select {
  display: none; /*hide original SELECT element:*/
}
.select-selected {
  background-color: #f4a137;
}
/*style the arrow inside the select element:*/
.select-selected:after {
  position: absolute;
  content: "";
  top: 14px;
  right: 10px;
  width: 0;
  height: 0;
  border: 6px solid transparent;
  border-color: #fff transparent transparent transparent;
}
/*point the arrow upwards when the select box is open (active):*/
.select-selected.select-arrow-active:after {
  border-color: transparent transparent #fff transparent;
  top: 7px;
}
/*style the items (options), including the selected item:*/
.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: #f4a137;
  top: 100%;
  left: 0;
  right: 0;
  z-index: 99;
}
/*hide the items when the select box is closed:*/
.select-hide {
  display: none;
}
.select-items div:hover, .same-as-selected {
  background-color: rgba(0, 0, 0, 0.1);
}
    </style>

Answer 1

所以...你使用一个插件来获得一个“发烧友”select ...

该插件会创建一些新的 DOM 元素...因此用户不会真正与原始标记的选择进行交互。它仅用于创建新的...然后隐藏。

这是作为您的 <form> 的 sibling 创建的内容:

<div class="custom-select" style="width: 200px">
  <form method="get" name="rate">

    <select name="rate2" id="rate2">

      <option value="0">Broj Rata:</option>
      <option value="2">2</option>
      <option value="3">3</option>
      <option value="4">4</option>
      <option value="5">5</option>
      <option value="6">6</option>
      <option value="7">7</option>
      <option value="8">8</option>
      <option value="9">9</option>
      <option value="10">10</option>
      <option value="11">11</option>
      <option value="12">12</option>
    </select>
  </form>
  <div class="select-selected">
    Broj Rata:
  </div>
  <div class="select-items select-hide">
    <div>Broj Rata:</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
    <div>5</div>
    <div>6</div>
    <div>7</div>
    <div>8</div>
    <div>9</div>
    <div>10</div>
    <div>11</div>
    <div>12</div>
  </div>
</div>

因此我们现在需要使用另一个选择器来捕获用户交互。

替换:

$("#rate2").on('change', function() {

与

$("[name='rate']+.select-selected+.select-items").on("click",function(){

---

+登录选择器是一个 "adjacent sibling selector" .它以最后一个为目标 IF 它紧跟在前一个之后(作为 DOM 中的同级)。

这就很好地解决了这个问题。

CodePen