在 Javascript 中隐藏搜索元素答案

【问题标题】：Hide search elements in Javascript在 Javascript 中隐藏搜索元素
【发布时间】：2022-07-21 21:33:35
【问题描述】：

在下面的示例代码中，我想隐藏搜索字段下显示的元素。代码来自 W3：https://www.w3schools.com/howto/howto_js_filter_lists.asp 搜索元素应仅在用户开始在搜索字段中输入时显示。没有什么复杂的，只是为初学者寻找解决方案。谢谢

    <!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
* {
  box-sizing: border-box;
}

#myInput {
  background-image: url('/css/searchicon.png');
  background-position: 10px 12px;
  background-repeat: no-repeat;
  width: 100%;
  font-size: 16px;
  padding: 12px 20px 12px 40px;
  border: 1px solid #ddd;
  margin-bottom: 12px;
}

#myUL {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

#myUL li a {
  border: 1px solid #ddd;
  margin-top: -1px; /* Prevent double borders */
  background-color: #f6f6f6;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  color: black;
  display: block
}

#myUL li a:hover:not(.header) {
  background-color: #eee;
}
</style>
</head>
<body>

<h2>My Phonebook</h2>

<input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names.." title="Type in a name">

<ul id="myUL">
  <li><a href="#">Adele</a></li>
  <li><a href="#">Agnes</a></li>

  <li><a href="#">Billy</a></li>
  <li><a href="#">Bob</a></li>

  <li><a href="#">Calvin</a></li>
  <li><a href="#">Christina</a></li>
  <li><a href="#">Cindy</a></li>
</ul>

<script>
function myFunction() {
    var input, filter, ul, li, a, i, txtValue;
    input = document.getElementById("myInput");
    filter = input.value.toUpperCase();
    ul = document.getElementById("myUL");
    li = ul.getElementsByTagName("li");
    for (i = 0; i < li.length; i++) {
        a = li[i].getElementsByTagName("a")[0];
        txtValue = a.textContent || a.innerText;
        if (txtValue.toUpperCase().indexOf(filter) > -1) {
            li[i].style.display = "";
        } else {
            li[i].style.display = "none";
        }
    }
}
</script>

</body>
</html>

【问题讨论】：

标签： javascript html css

【解决方案1】：

只需将display: none 设置为#myUL li

#myUL li {
  display: none;
}

并更改您的js 添加li[i].style.display = "block"

if (txtValue.toUpperCase().indexOf(filter) > -1) {
  li[i].style.display = "block";
} else {
  li[i].style.display = "none";
}

工作示例

function myFunction() {
  var input, filter, ul, li, a, i, txtValue;
  input = document.getElementById("myInput");
  filter = input.value.toUpperCase();
  ul = document.getElementById("myUL");
  li = ul.getElementsByTagName("li");
  for (i = 0; i < li.length; i++) {
    a = li[i].getElementsByTagName("a")[0];
    txtValue = a.textContent || a.innerText;
    if (txtValue.toUpperCase().indexOf(filter) > -1) {
      li[i].style.display = "block";
    } else {
      li[i].style.display = "none";
    }
  }
}

* {
  box-sizing: border-box;
}

#myInput {
  background-image: url('/css/searchicon.png');
  background-position: 10px 12px;
  background-repeat: no-repeat;
  width: 100%;
  font-size: 16px;
  padding: 12px 20px 12px 40px;
  border: 1px solid #ddd;
  margin-bottom: 12px;
}

#myUL {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

#myUL li {
  display: none
}

#myUL li a {
  border: 1px solid #ddd;
  margin-top: -1px;
  /* Prevent double borders */
  background-color: #f6f6f6;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  color: black;
  display: block
}

#myUL li a:hover:not(.header) {
  background-color: #eee;
}

<h2>My Phonebook</h2>

<input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names.." title="Type in a name">

<ul id="myUL">
  <li><a href="#">Adele</a></li>
  <li><a href="#">Agnes</a></li>

  <li><a href="#">Billy</a></li>
  <li><a href="#">Bob</a></li>

  <li><a href="#">Calvin</a></li>
  <li><a href="#">Christina</a></li>
  <li><a href="#">Cindy</a></li>
</ul>

【讨论】：

【解决方案2】：

不是优雅的解决方案，但有助于您了解脚本的工作原理，从一开始就将 style="display:none" 添加到 li：

<ul id="myUL">
  <li style="display:none"><a href="#">Adele</a></li>
  <li style="display:none"><a href="#">Agnes</a></li>

  <li style="display:none"><a href="#">Billy</a></li>
  <li style="display:none"><a href="#">Bob</a></li>

  <li style="display:none"><a href="#">Calvin</a></li>
  <li style="display:none"><a href="#">Christina</a></li>
  <li style="display:none"><a href="#">Cindy</a></li>
</ul>

【讨论】：