如果用户单击第二个下拉链接，则关闭下拉菜单

Question

我有一个带有多个下拉菜单的导航栏。 因此，当我单击第一个链接时，它将打开下拉列表，但是当我单击第二个链接时，第一个下拉列表不会关闭。 （因此，如果用户单击第二个链接，我想关闭下拉菜单）

 // main.js (javascript file) function myFunction() { var x = document.getElementById("myTopnav1"); if (x.className === "topnav1") { x.className += " responsive1"; } else { x.className = "topnav1"; } } function toggleDropDown(myid) { var element = document.getElementById(myid); element.classList.toggle("mystyle"); } // Close the dropdown menu if the user clicks outside of it window.onclick = function(event) { if (!event.target.matches('.dropbtn1')) { var dropdowns = document.getElementsByClassName("dropdown-content1"); var i; for (i = 0; i < dropdowns.length; i++) { var openDropdown = dropdowns[i]; if (openDropdown.classList.contains('mystyle')) { openDropdown.classList.remove('mystyle'); } } } } 

 /* style.css (css file - css is all correct if anything you think is not added i only need help with javascript) */ .topnav1 { background-color: blue !important; } /* Style the links inside the navigation bar */ .topnav1 a { float: left; display: block; color: black; text-align: center; padding: 4px 8px; text-decoration: none; font-size: 10px; border-bottom: 1px solid #FDFDFD; } .topnav-right1 { float: right; } @media only screen and (max-width:768px) { .topnav-right1 { float: left; } } .para-active { background-color: #4F7ADA !important; color: black !important; } .para-active button { color: white !important; } /* Add an active class to highlight the current page */ .active1 { color: black !important; } /* Hide the link that should open and close the topnav on small screens */ .topnav1 .icon { display: none; } /* Dropdown container - needed to position the dropdown content */ .dropdown1 { float: left; overflow: hidden; background-color: #f1f1f1; border-bottom: 1px solid #E3E3E3; } /* Style the dropdown button to fit inside the topnav */ .dropdown1 .dropbtn1 { font-size: 10px; border: none; outline: none; color: black; padding: 4px 8px; background-color: inherit; font-family: inherit; margin: 0; border-bottom: 1px solid #FDFDFD; } /* Style the dropdown content (hidden by default) */ .dropdown-content1 { display: none; position: absolute; background-color: #f9f9f9; min-width: 96px; box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2); z-index: 1; } .mystyle { display: block; } 

 <div class="topnav1" id="myTopnav1"> <div class="dropdown1"> <button style="display: none;" id="btn_em" onclick="toggleDropDown('div_em')" class="dropbtn1">Meters </button> <div class="dropdown-content1" id="div_em"> <label class="dropnav-container">one</label> <label class="dropnav-container">one</label> <label class="dropnav-container">one</label> </div> </div> <div class="dropdown1"> <button id="btn_inv" onclick="toggleDropDown('div_inv')" class="dropbtn1">Inverters </button> <div class="dropdown-content1" id="div_inv"> <label class="dropnav-container">two</label> <label class="dropnav-container">two</label> <label class="dropnav-container">two</label> </div> </div> <div class="dropdown1"> <button id="btn_inm" onclick="toggleDropDown('div_inm')" class="dropbtn1">Inverter Manager </button> <div class="dropdown-content1" id="div_inm"> <label class="dropnav-container">three</label> <label class="dropnav-container">three</label> <label class="dropnav-container">three</label> </div> </div> <div class="dropdown1"> <button id="btn_ws" onclick="toggleDropDown('div_ws')" class="dropbtn1">Sensors </button> <div class="dropdown-content1" id="div_ws"> <label class="dropnav-container">four</label> <label class="dropnav-container">four</label> <label class="dropnav-container">four</label> </div> </div> <div class="dropdown1"> <button id="btn_smu" onclick="toggleDropDown('div_smu')" class="dropbtn1">SMUs </button> <div class="dropdown-content1" id="div_smu"> <label class="dropnav-container">five</label> <label class="dropnav-container">five</label> <label class="dropnav-container">five</label> </div> </div> <a href="javascript:void(0);" class="icon" onclick="myFunction()">&#9776;</a> </div> 

Answer 1

如果要使用JavaScript进行此功能，则必须在打开新的下拉菜单后使用id来关闭其他下拉菜单。

因此，我正在研究的解决方案是创建一个新方法closeMenus ，一旦执行toggleDropDown ，它将关闭其他下拉菜单。

 function myFunction() { var x = document.getElementById("myTopnav1"); if (x.className === "topnav1") { x.className += " responsive1"; } else { x.className = "topnav1"; } } function toggleDropDown(myid) { closeMenus(myid); var element = document.getElementById(myid); element.classList.toggle("mystyle"); } function closeMenus(currentId) { var dropdowns = document.getElementsByClassName("dropdown-content1"); var i; for (i = 0; i < dropdowns.length; i++) { var openDropdown = dropdowns[i]; if (openDropdown.classList.contains('mystyle') && openDropdown.id !== currentId) { openDropdown.classList.remove('mystyle'); } } } // Close the dropdown menu if the user clicks outside of it window.onclick = function(event) { if (!event.target.matches('.dropbtn1')) { closeMenus(); } } 

 .topnav1 { background-color: blue !important; } /* Style the links inside the navigation bar */ .topnav1 a { float: left; display: block; color: black; text-align: center; padding: 4px 8px; text-decoration: none; font-size: 10px; border-bottom: 1px solid #FDFDFD; } .topnav-right1 { float: right; } @media only screen and (max-width:768px) { .topnav-right1 { float: left; } } .para-active { background-color: #4F7ADA !important; color: black !important; } .para-active button { color: white !important; } /* Add an active class to highlight the current page */ .active1 { color: black !important; } /* Hide the link that should open and close the topnav on small screens */ .topnav1 .icon { display: none; } /* Dropdown container - needed to position the dropdown content */ .dropdown1 { float: left; overflow: hidden; background-color: #f1f1f1; border-bottom: 1px solid #E3E3E3; } /* Style the dropdown button to fit inside the topnav */ .dropdown1 .dropbtn1 { font-size: 10px; border: none; outline: none; color: black; padding: 4px 8px; background-color: inherit; font-family: inherit; margin: 0; border-bottom: 1px solid #FDFDFD; } /* Style the dropdown content (hidden by default) */ .dropdown-content1 { display: none; position: absolute; background-color: #f9f9f9; min-width: 96px; box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2); z-index: 1; } .mystyle { display: block; } 

 <div class="topnav1" id="myTopnav1"> <div class="dropdown1"> <button style="display: none;" id="btn_em" onclick="toggleDropDown('div_em')" class="dropbtn1">Meters </button> <div class="dropdown-content1" id="div_em"> <label class="dropnav-container">one</label> <label class="dropnav-container">one</label> <label class="dropnav-container">one</label> </div> </div> <div class="dropdown1"> <button id="btn_inv" onclick="toggleDropDown('div_inv')" class="dropbtn1">Inverters </button> <div class="dropdown-content1" id="div_inv"> <label class="dropnav-container">two</label> <label class="dropnav-container">two</label> <label class="dropnav-container">two</label> </div> </div> <div class="dropdown1"> <button id="btn_inm" onclick="toggleDropDown('div_inm')" class="dropbtn1">Inverter Manager </button> <div class="dropdown-content1" id="div_inm"> <label class="dropnav-container">three</label> <label class="dropnav-container">three</label> <label class="dropnav-container">three</label> </div> </div> <div class="dropdown1"> <button id="btn_ws" onclick="toggleDropDown('div_ws')" class="dropbtn1">Sensors </button> <div class="dropdown-content1" id="div_ws"> <label class="dropnav-container">four</label> <label class="dropnav-container">four</label> <label class="dropnav-container">four</label> </div> </div> <div class="dropdown1"> <button id="btn_smu" onclick="toggleDropDown('div_smu')" class="dropbtn1">SMUs </button> <div class="dropdown-content1" id="div_smu"> <label class="dropnav-container">five</label> <label class="dropnav-container">five</label> <label class="dropnav-container">five</label> </div> </div> <a href="javascript:void(0);" class="icon" onclick="myFunction()">&#9776;</a> </div> 

Answer 2

我假设您的mystyle类使下拉菜单处于活动状态。 然后你可以做这样的事情

// Get all the dropdowns
var dropdowns = document.getElementByClassName(".dropdown1")

// When clicked on dropdown this function will fire
var callThisFunction = function (e) {
    // Check the event
    e = e || window.event;

    // Get the target element
    let target = e.target || e.srcElement;

    // Close all dropdowns
    let activeDropdowns = document.getElementsByClassName("mystyle");
    activeDropdowns.forEach(function (openDropdown) {
          openDropdown.classList.remove('mystyle');
    })

    // Make the current dropdown active
    target.className += 'mystyle'
}

// This adds click event listener to all dropdowns and tells it to fire callThisFunction when clicked

dropdowns.forEach(function (dropdown) {
    dropdown[i].addEventListener('click', callThisFunction, false);
})

Answer 3

我建议您使用JQUERY （以下CDN）

https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.js

jQuery超快速且实用
因为您的问题将在jquery中这样解决。

$('.yourdropdownsclass').on('click', function(){
   var target = $(this).attr('id');
   $("#"+target).show().siblings("div").hide();
});

.yourdropdownclass

是您的下拉菜单的类别

$（this）.attr（'id'）

这是另一个下拉列表的ID。

$（“＃” + target）.show（）。siblings（“ div”）。hide（）;

“目标”是其他下拉列表的ID的名称，并将其存储到变量中并显示出来并隐藏另一个兄弟的下拉列表。 希望对您有帮助！