如何延迟删除下拉菜单Bootstrap 4的类？

Question

我正在尝试在导航栏上切换一个类切换，但是当您移动鼠标时，下拉菜单会快速删除该类并隐藏菜单。我认为它需要的只是延迟课程的移除，但课程的表现仍然是即时的。以下是悬停问题https://i.imgur.com/o8ccCn9.gifv

的屏幕截图

是否有手动方式来编写切换？

Codepen：https://codepen.io/JacobLett/pen/jaaQYG?editors=0110

这是到目前为止的脚本

$(document).ready(function() {
 // executes when HTML-Document is loaded and DOM is ready

  // when you hover a toggle show its dropdown menu
  $(".navbar .dropdown-toggle").hover(function () {
     $(this).parent().toggleClass("show");
     $(this).parent().find(".dropdown-menu").toggleClass("show"); 
   });

    // hide the menu when the mouse leaves the dropdown
  $( ".navbar .dropdown-menu" ).mouseleave(function() {
    $(this).removeClass("show");  
  });

// document ready  
});

更新我猜.hover没有考虑子元素。如果它确实我的代码将工作。所以我尝试了mouseenter和mouseleave，但由于下拉列表是绝对位置，所以它也不适用。

Answer 1

您可以使用native JavaScript setTimeout() method ...

$(document).ready(function() {
 // executes when HTML-Document is loaded and DOM is ready

  // when you hover a toggle show its dropdown menu
  $(".navbar .dropdown-toggle").hover(function () {
     $(this).parent().toggleClass("show");
     $(this).parent().find(".dropdown-menu").toggleClass("show"); 
   });

    // hide the menu when the mouse leaves the dropdown
  $( ".navbar .dropdown-menu" ).mouseleave(function() {
    setTimeout(function() {
      $(this).removeClass("show");
    }, 3000); // delay the removal of the 'show' class for 3 seconds
  });

// document ready  
});

Answer 2

好的，在尝试了几个javascript选项后，我想起了一个好的旧suckerfish菜单，你将下拉菜单向上移动几个像素，这样悬停状态不会因为你在锚点触发器和菜单本身之间的间隙上空盘旋而破坏

所以我保持我的脚本相同，但只在桌面宽度上解雇它，然后调整我的CSS以消除悬停间隙。

最终解决方案：https://codepen.io/JacobLett/pen/jaaQYG

<强> HTML

<nav class="navbar navbar-expand-lg navbar-dark bg-primary">
  <a class="navbar-brand" href="#">Mega Dropdown</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item">
        <a class="nav-link" href="#">Category</a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Category 1
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">


          <div class="container">
            <div class="row">
              <div class="col-md-4">
                <ul class="nav flex-column">
                <li class="nav-item">
                  <a class="nav-link active" href="#">Active</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
              </ul>
              </div>
              <!-- /.col-md-4  -->
              <div class="col-md-4">
                <ul class="nav flex-column">
                <li class="nav-item">
                  <a class="nav-link active" href="#">Active</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
              </ul>
              </div>
              <!-- /.col-md-4  -->
              <div class="col-md-4">
                <a href="">
                  <img src="https://dummyimage.com/200x100/ccc/000&text=image+link" alt="" class="img-fluid">
                </a>
                <p class="text-white">Short image call to action</p>

              </div>
              <!-- /.col-md-4  -->
            </div>
          </div>
          <!--  /.container  -->


        </div>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Category 2
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">


          <div class="container">
            <div class="row">
              <div class="col-md-4">
                <ul class="nav flex-column">
                <li class="nav-item">
                  <a class="nav-link active" href="#">Active</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
              </ul>
              </div>
              <!-- /.col-md-4  -->
              <div class="col-md-4">
                <ul class="nav flex-column">
                <li class="nav-item">
                  <a class="nav-link active" href="#">Active</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
              </ul>
              </div>
              <!-- /.col-md-4  -->
              <div class="col-md-4">
                <a href="">
                  <img src="https://dummyimage.com/200x100/ccc/000&text=image+link" alt="" class="img-fluid">
                </a>
                <p class="text-white">Short image call to action</p>

              </div>
              <!-- /.col-md-4  -->
            </div>
          </div>
          <!--  /.container  -->


        </div>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Category 3
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">


          <div class="container">
            <div class="row">
              <div class="col-md-4">
                <ul class="nav flex-column">
                <li class="nav-item">
                  <a class="nav-link active" href="#">Active</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
              </ul>
              </div>
              <!-- /.col-md-4  -->
              <div class="col-md-4">
                <ul class="nav flex-column">
                <li class="nav-item">
                  <a class="nav-link active" href="#">Active</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
                <li class="nav-item">
                  <a class="nav-link" href="#">Link item</a>
                </li>
              </ul>
              </div>
              <!-- /.col-md-4  -->
              <div class="col-md-4">

                <a href="">
                  <img src="https://dummyimage.com/200x100/ccc/000&text=image+link" alt="" class="img-fluid">
                </a>
                <p class="text-white">Short image call to action</p>

              </div>
              <!-- /.col-md-4  -->
            </div>
          </div>
          <!--  /.container  -->


        </div>
      </li>

    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-light my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>


</nav>

<强> CSS

/* adds some margin below the link sets  */
.navbar .dropdown-menu div[class*="col"] {
   margin-bottom:1rem;
}

.navbar .dropdown-menu {
  border:none;
  background-color:#0060c8!important;
}

/* breakpoint and up - mega dropdown styles */
@media screen and (min-width: 992px) {

  /* remove the padding from the navbar so the dropdown hover state is not broken */
.navbar {
  padding-top:0px;
  padding-bottom:0px;
}

/* remove the padding from the nav-item and add some margin to give some breathing room on hovers */
.navbar .nav-item {
  padding:.5rem .5rem;
  margin:0 .25rem;
}

/* makes the dropdown full width  */
.navbar .dropdown {position:static;}

.navbar .dropdown-menu {
  width:100%;
  left:0;
  right:0;
/*  height of nav-item  */
  top:45px;
}

  /* shows the dropdown menu on hover */
.navbar .dropdown:hover .dropdown-menu, .navbar .dropdown .dropdown-menu:hover {
  display:block!important;
}

  .navbar .dropdown-menu {
    border: 1px solid rgba(0,0,0,.15);
    background-color: #fff;
  }

}

<强> JS

$(document).ready(function() {
 // executes when HTML-Document is loaded and DOM is ready

// breakpoint and up  
$(window).resize(function(){
    if ($(window).width() >= 980){  

      // when you hover a toggle show its dropdown menu
      $(".navbar .dropdown-toggle").hover(function () {
         $(this).parent().toggleClass("show");
         $(this).parent().find(".dropdown-menu").toggleClass("show"); 
       });

        // hide the menu when the mouse leaves the dropdown
      $( ".navbar .dropdown-menu" ).mouseleave(function() {
        $(this).removeClass("show");  
      });

        // do something here
    }   
});  



// document ready  
});