Question

我有一个带有2个选项的菜单栏，显示点击下拉菜单，从技术上来说，即使你只点击一个，它们都显示出来。我想要做的就是在点击其他菜单项后隐藏其他下拉列表。

我的代码出了什么问题？

BODY：

<body>
    <ul>
  <li class="File">
    <a href="javascript:void(0)" class="dropbtn" onclick="myFunction()">File</a>
    <div class="dropdown-content" id="myDropdown">
      <a href="#">Open</a>
      <a href="#">Save</a>
      <a href="#">Save As</a>
      <a href="#">Close</a>
    </div>
    <li class="Edit">
    <a href="javascript:void(0)" class="dropbtn" onclick="myFunction()">Edit</a>
    <div class="dropdown-content" id="myDropdown2">
      <a href="#">Undo</a>
      <a href="#">Redo</a>
      <a href="#">Cut</a>
      <a href="#">Copy</a>
      <a href="#">Paste</a>
    </div>
  </li>
</ul>
<div id="TITLE" style="font-family: verdana; font-size: 36px; margin-left: 1200px; margin-top: -45px; color: white;">
    PANTS
</div>
<!-- THE FUNCTION FOR CLICK -->
<script>
var drptochoose;
function myFunction() {
    document.getElementById("myDropdown").classList.toggle("show");
    document.getElementById("myDropdown2").classList.toggle("show");
}

window.onclick = function(e) {
  if (!e.target.matches('.dropbtn')) {

    var dropdowns = document.getElementsByClassName("dropdown-content");
    for (var d = 0; d < dropdowns.length; d++) {
      var openDropdown = dropdowns[d];
      if (openDropdown.classList.contains('show')) {
        openDropdown.classList.remove('show');
      }
    }
  }
}
</script>
<!-- END OF FUNCTION FOR CLICK -->
    </body>

CSS：

<style>
ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: green;
    font-family: verdana;
    font-size: 14px;
}

li {
    float: left;
}

li a, .dropbtn {
    display: inline-block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

li a:hover, .dropdown:hover .dropbtn {
    background-color: red;
}

li.dropdown {
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
}

.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
}

.dropdown-content a:hover {background-color: #f1f1f1}

.show {display:block;}
<script src="jquery.js"></script>
        </style>

Answer 1

您的代码存在的问题是它会切换两个下拉列表。因此，当他们都没有出现时，他们会得到这个课程。

您可以这样做：

<body>
  <ul>
    <li class="File">
      <a href="javascript:void(0)" class="dropbtn" onclick="myFunction(myDropdown)">File</a>
      <div class="dropdown-content" id="myDropdown">
        <a href="#">Open</a>
        <a href="#">Save</a>
        <a href="#">Save As</a>
        <a href="#">Close</a>
      </div>
    </li>
    <li class="Edit">
      <a href="javascript:void(0)" class="dropbtn" onclick="myFunction(myDropdown2)">Edit</a>
      <div class="dropdown-content" id="myDropdown2">
        <a href="#">Undo</a>
        <a href="#">Redo</a>
        <a href="#">Cut</a>
        <a href="#">Copy</a>
        <a href="#">Paste</a>
      </div>
    </li>
  </ul>
  <div id="TITLE" style="font-family: verdana; font-size: 36px; margin-left: 1200px; margin-top: -45px; color: white;">
    PANTS
  </div>
  <!-- THE FUNCTION FOR CLICK -->

  <script>
    var drptochoose;

    function hideDropdowns(excludeId) {
      var dropdowns = document.getElementsByClassName("dropdown-content");
      for (var d = 0; d < dropdowns.length; d++) {
        var openDropdown = dropdowns[d];
        if (openDropdown.classList.contains('show') && excludeId !== openDropdown.id) {
          openDropdown.classList.remove('show');
        }
      }
    }

    function myFunction(id) {
      id.classList.toggle("show");
      hideDropdowns(id.id);
    }

    window.onclick = function(e) {
      if (!e.target.matches('.dropbtn')) {
        hideDropdowns();
      }
    }
  </script>

  <!-- END OF FUNCTION FOR CLICK -->
</body>

Answer 2

你需要这样的东西

jsFiddleDemoNavBar

Answer 3

我不认为你需要通过所有代码来完成你所理解的事情。只需使用.hide类在页面加载时默认隐藏下拉菜单，然后使用按钮onclick with call（this）和nextElementSibling来切换它们。

这是代码。

＆＃13;

    <style>
    .hide{
  display:none;
}
    </style>
    <body>
    <ul>
  <li class="File">
    <a href="javascript:void(0)" class="dropbtn" onclick="myFunction.call(this)">File</a>
    <div class="dropdown-content hide" id="myDropdown">
      <a href="#">Open</a>
      <a href="#">Save</a>
      <a href="#">Save As</a>
      <a href="#">Close</a>
    </div>
    </li>
    <li class="Edit">
    <a href="javascript:void(0)" class="dropbtn" onclick="myFunction.call(this)">Edit</a>
    <div class="dropdown-content hide" id="myDropdown2">
      <a href="#">Undo</a>
      <a href="#">Redo</a>
      <a href="#">Cut</a>
      <a href="#">Copy</a>
      <a href="#">Paste</a>
    </div>
  </li>
</ul>
<div id="TITLE" style="font-family: verdana; font-size: 36px; margin-left: 1200px; margin-top: -45px; color: white;">
    PANTS
</div>
<script>
var drptochoose;
function myFunction() {
		var isAlreadyOpen = false;
		if(!this.nextElementSibling.classList.contains('hide'))
    {
    	// if the clicked button dropdown is already open then use this bool to not show it again.
    	isAlreadyOpen = true;
    }
    var dropdowns = document.getElementsByClassName("dropdown-content");
    for (var d = 0; d < dropdowns.length; d++) {
      var openDropdown = dropdowns[d];
      if (!openDropdown.classList.contains('hide')) {
        openDropdown.classList.toggle("hide");
      }
    }
    if(!isAlreadyOpen)
    {
    	// if the dropdown was hidden when clicked then show it
    	this.nextElementSibling.classList.toggle("hide");    
    }
}

</script>
</body>

＆＃13;

希望这有帮助。

Answer 4

window.onclick = function(e) {
      if (e.target.matches('.dropbtn')) {
          var allDropDown = document.querySelectorAll('.dropdown-content');

         //This will hide all the dropdown for everytime you click
         [].forEach.call(allDropdown, function(dropdown){
            dropdown.classList.add('hide');
         });

         //This will show the subdrop down of that menu
         var dropdown = e.target.parent.querySelector(".dropdown-content");
         dropdown.classList.add('show');
      }
   }
}

如何在选择其他下拉时隐藏其他下拉列表

4 个答案: