javascript - 将悬停区域扩展到外部元素

Question

我有一个下拉菜单，子菜单放在不同的元素上。所以基本上当鼠标离开菜单项时，子菜单会立即关闭，因为子菜单不是子菜单。

var menuItem = $(".menu-item");


menuItem.hover(hoverIn, hoverOut);

function hoverIn() {
  var mnItemMeta = $(this)[0].getBoundingClientRect();

  $(".sub-menu").css({
    opacity: 1,
    left: mnItemMeta.left
  })
}

function hoverOut() {
  $(".sub-menu").css({
    opacity: 0
  })
}

html,body{background-color: #efefef;}
.menu {
  list-style: none;
  padding-left: 0;
  display: flex;
  justify-content: center;
}
a {
  display: block;
  padding: 10px 20px;
  text-decoration: none;
  color: inherit;
}
.sub-menu {
  opacity: 0;
  background-color: white;
  position: absolute;
  transition: .2s ease;
}
.sub-menu-list {
  list-style: none;
  padding-left: 0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<ul class="menu">
  <li class="menu-item"><a href="#">Menu Item</a>
  </li>
</ul>
<div class="sub-menu">
  <ul class="sub-menu-list">
    <li><a href="#">Sub Menu 1</a>
    </li>
    <li><a href="#">Sub Menu 2</a>
    </li>
    <li><a href="#">Sub Menu 3</a>
    </li>
    <li><a href="#">Sub Menu 4</a>
    </li>
  </ul>
</div>

https://jsfiddle.net/yans_fied/6wj0of90/

问题是如何扩展悬停区域，因此当光标指向子菜单时，它会忽略 hoverOut 操作。

注意:不要告诉我将子菜单放在菜单项中，我已经知道它是如何工作的。这是针对需要将子菜单放置在菜单项之外的不同情况。

Answer 1

您可以将子菜单放在menu-item中。

var menuItem = $(".menu-item");
menuItem.hover(hoverIn, hoverOut);

function hoverIn() {
  var mnItemMeta = $(this)[0].getBoundingClientRect();

  $(".sub-menu").css({
    opacity: 1,
    left: mnItemMeta.left
  })
}

function hoverOut() {
  $(".sub-menu").css({
    opacity: 0
  })
}

html, body {
  background-color: #efefef;
}
.menu {
  list-style: none;
  padding-left: 0;
  display: flex;
  justify-content: center;
}
a {
  display: block;
  padding: 10px 20px;
  text-decoration: none;
  color: inherit;
}
.sub-menu {
  opacity: 0;
  background-color: white;
  position: absolute;
  transition: .2s ease;
}
.sub-menu-list {
  list-style: none;
  padding-left: 0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

<ul class="menu">
  <li class="menu-item"><a href="#">Menu Item</a>
    <div class="sub-menu">
      <ul class="sub-menu-list">
        <li><a href="#">Sub Menu 1</a></li>
        <li><a href="#">Sub Menu 2</a></li>
        <li><a href="#">Sub Menu 3</a></li>
        <li><a href="#">Sub Menu 4</a></li>
      </ul>
    </div>
  </li>
</ul>

另一种方法是检查.menu-item 和.sub-menu 的hover 状态。您需要在此处设置一点超时，以防止它提前关闭。

var timeout,
    hovered = false,
    menuItem = $(".menu-item, .sub-menu").hover(hoverIn, hoverOut);;

function hoverIn() {
    hovered = true;

    var mnItemMeta = this.getBoundingClientRect();

    $(".sub-menu").show().css({
        opacity: 1,
        left: mnItemMeta.left,
    });
}

function hoverOut() {
  hovered = false;

    clearTimeout(timeout);
    timeout = setTimeout(function() {
        if (!hovered) {
            $(".sub-menu").css({
                opacity: 0,
            }).hide()
        }
    }, 100);
}

html, body {
  background-color: #efefef;
}
.menu {
  list-style: none;
  padding-left: 0;
  display: flex;
  justify-content: center;
}
a {
  display: block;
  padding: 10px 20px;
  text-decoration: none;
  color: inherit;
}
.sub-menu {
  opacity: 0;
  background-color: white;
  position: absolute;
  transition: .2s ease;
}
.sub-menu-list {
  list-style: none;
  padding-left: 0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

<ul class="menu">
  <li class="menu-item"><a href="#">Menu Item</a></li>
</ul>
<div class="sub-menu">
  <ul class="sub-menu-list">
    <li><a href="#">Sub Menu 1</a></li>
    <li><a href="#">Sub Menu 2</a></li>
    <li><a href="#">Sub Menu 3</a></li>
    <li><a href="#">Sub Menu 4</a></li>
  </ul>
</div>