Bootstrap3下拉子菜单始终处于打开状态

Question

我正在通过此链接创建子菜单下拉列表：

https://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_ref_js_dropdown_events2&stacked=h

但是我的所有子菜单始终处于打开状态，我希望它能够正常工作，这意味着子菜单仅在将鼠标悬停在父菜单上（即我使用引导程序3.3.7）时才会显示。

这是描述图像，当我按下“ CLICK”按钮时，子菜单也始终处于打开状态（菜单3和菜单4）

这是我的代码：

<div class="dropdown">
    <button class="btn btn-default dropdown-toggle" type="button" data-toggle="dropdown">CLICK
    <span class="caret"></span></button>
    <ul class="dropdown-menu">
      <li><a tabindex="-1" href="#">MENU 1</a></li>
      <li><a tabindex="-1" href="#">MENU 2</a></li>
      <li class="dropdown-submenu">
        <a class="test" tabindex="-1" href="#">MENU 3</a>
        <ul class="dropdown-menu">
          <li><a tabindex="-1" href="#">MENU 3.1</a></li>
          <li><a tabindex="-1" href="#">MENU 3.2</a></li>
        </ul>
      </li>
      <li class="dropdown-submenu">
        <a class="test" tabindex="-1" href="#">MENU 4</a>
        <ul class="dropdown-menu">
          <li><a tabindex="-1" href="#">MENU 4.1</a></li>
          <li><a tabindex="-1" href="#">MENU 4.2</a></li>
        </ul>
      </li>
    </ul>
</div>


// style
.dropdown-submenu {
    position: relative;
}

.dropdown-submenu>.dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -6px;
    margin-left: -1px;
    -webkit-border-radius: 0 6px 6px 6px;
    -moz-border-radius: 0 6px 6px;
    border-radius: 0 6px 6px 6px;
}

.dropdown-submenu:hover>.dropdown-menu {
    display: block;
}

.dropdown-submenu>a:after {
    display: block;
    content: " ";
    float: right;
    width: 0;
    height: 0;
    border-color: transparent;
    border-style: solid;
    border-width: 5px 0 5px 5px;
    border-left-color: #ccc;
    margin-top: 5px;
    margin-right: -10px;
}

.dropdown-submenu:hover>a:after {
    border-left-color: #fff;
}

.dropdown-submenu.pull-left {
    float: none;
}

.dropdown-submenu.pull-left>.dropdown-menu {
    left: -100%;
    margin-left: 10px;
    -webkit-border-radius: 6px 0 6px 6px;
    -moz-border-radius: 6px 0 6px 6px;
    border-radius: 6px 0 6px 6px;
}

Answer 1

您应该使用display：none，然后在悬停时使用display：block

// style
.dropdown-submenu {
    position: relative;
}

.dropdown-submenu>.dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -6px;
    margin-left: -1px;
    -webkit-border-radius: 0 6px 6px 6px;
    -moz-border-radius: 0 6px 6px;
    border-radius: 0 6px 6px 6px;
}
.dropdown-submenu .dropdown-menu {
    display: none;
}
.dropdown-submenu:hover>.dropdown-menu {
    display: block;
}

.dropdown-submenu>a:after {
    display: block;
    content: " ";
    float: right;
    width: 0;
    height: 0;
    border-color: transparent;
    border-style: solid;
    border-width: 5px 0 5px 5px;
    border-left-color: #ccc;
    margin-top: 5px;
    margin-right: -10px;
}

.dropdown-submenu:hover>a:after {
    border-left-color: #fff;
}

.dropdown-submenu.pull-left {
    float: none;
}

.dropdown-submenu.pull-left>.dropdown-menu {
    left: -100%;
    margin-left: 10px;
    -webkit-border-radius: 6px 0 6px 6px;
    -moz-border-radius: 6px 0 6px 6px;
    border-radius: 6px 0 6px 6px;
}

<div class="dropdown">
                        <button class="btn btn-default dropdown-toggle" type="button" data-toggle="dropdown">CLICK
                        <span class="caret"></span></button>
                        <ul class="dropdown-menu">
                          <li><a tabindex="-1" href="#">MENU 1</a></li>
                          <li><a tabindex="-1" href="#">MENU 2</a></li>
                          <li class="dropdown-submenu">
                            <a class="test" tabindex="-1" href="#">MENU 3</a>
                            <ul class="dropdown-menu">
                              <li><a tabindex="-1" href="#">MENU 3.1</a></li>
                              <li><a tabindex="-1" href="#">MENU 3.2</a></li>
                            </ul>
                          </li>
                          <li class="dropdown-submenu">
                            <a class="test" tabindex="-1" href="#">MENU 4</a>
                            <ul class="dropdown-menu">
                              <li><a tabindex="-1" href="#">MENU 4.1</a></li>
                              <li><a tabindex="-1" href="#">MENU 4.2</a></li>
                            </ul>
                          </li>
                        </ul>
                    </div>