下拉菜单栏滑动意外错误答案

【问题标题】：Dropdown Menu Bar Slidedown Unexpected Error下拉菜单栏滑动意外错误
【发布时间】：2017-03-27 00:10:13
【问题描述】：

刚刚添加了我的整个页面，因为菜单栏没有完整显示。仍然需要帮助了解为什么幻灯片动画只在第一次鼠标悬停时出现。

我正在尝试使悬停时的下拉菜单使用 jquery 的 slideDown 和 slideUp 功能。我有它的工作......有点。菜单栏往往不会在第一次悬停时应用效果，然后再执行效果。然后它会一遍又一遍地做slideUp、slideDown、slideUp……。我尝试将函数包装在文档就绪函数中。我还尝试添加一个truthy if 语句，以便鼠标退出仅在菜单关闭时才有效。我似乎无法弄清楚这一点。任何帮助将不胜感激！

编辑：刚刚意识到 mouseout 是一个坏主意，因为当用户向下移动我的下拉菜单时，它也会向上滚动......关于另一种方式的建议？ HTML：

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Case</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
  <link href="css/custom.css" rel="stylesheet">
</head>
<body>
    <div id="custom-bootstrap-menu" class="navbar navbar-default " role="navigation">
    <div class="container-fluid">
        <div class="navbar-header"><a class="navbar-brand" href="#">Brand Logo</a>
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-menubuilder"><span class="sr-only">Toggle navigation</span><span class="icon-bar"></span><span class="icon-bar"></span><span class="icon-bar"></span>
            </button>
        </div>
        <div class="collapse navbar-collapse navbar-menubuilder">
            <ul class="nav navbar-nav navbar-left">
                <li class="active"><a href="#">Home</a>
                </li>
                <li class="dropdown">
                    <a href="#" class="dropdown-toggle slideDown" data-toggle="dropdown">Products<span class="caret"></span></a>
                    <ul class="dropdown-menu">
                        <li><a href="#">Option 1</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Option 2</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Option 3</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Option 4</a></li>
                    </ul>
                </li>
                <li><a href="/about-us">About Us</a>
                </li>
                <li><a href="/contact">Contact Us</a>
                </li>
            </ul>
        </div>
    </div>
</div>
      <div class="jumbotron text-center under">
    <div class="transparent vert-center">
    <h1 id="heading-title">Website Heading</h1>
      <p id="heading-desc">Information about the website!</p>
        </div>
    </div>
    <div class="container">
        <div class="row">
            <div class="col-sm-4 text-center outline">
                <h2>Text</h2>
                <p>More text describing the heading!</p>
                <span class="glyphicon glyphicon-leaf size"></span>

            </div>
                    <div class="col-sm-4 text-center outline">
                <h2>Text</h2>
                <p>More text describing the heading!</p>
                <span class="glyphicon glyphicon-hourglass size"></span>

            </div>

            <div class="col-sm-4 text-center outline">
                <h2>Text</h2>
                <p>More text describing the heading!</p>
                <span class="glyphicon glyphicon-plus size"></span>
            </div>

        </div>

    </div>
    <nav role="navigation" class="navbar navbar-bottom outline-above">
    <div class="container-fluid footer-bottom footer-top">
        <div class="row">
            <div class="col-sm-4 text-center">
                <h3 class="footer-heading footer-top">Footer Title</h3>
                <button type="button" class="btn-success btn-format">Click</button>
                <button type="button" id="button-margin-top1" class="btn-success btn-format">Click</button>
            </div>
            <div class="col-sm-4 text-center outline">
                <h3 class="footer-heading footer-top">Footer Title</h3>
                <button type="button" class="btn-success btn-format">Click</button>
                <button type="button" id="button-margin-top2" class="btn-success btn-format">Click</button>

            </div>

            <div class="col-sm-4 text-center">
                <h3 class="footer-heading footer-top">Footer Title</h3>
                <button type="button" class="btn-success btn-format">Click</button>
                <button type="button" id="button-margin-top3" class="btn-success btn-format">Click</button>
            </div>

        </div>
    </div>
    </nav>
<script>
$(function(){
$('.dropdown').hover(function(){
    $('.dropdown-menu').stop().slideDown(250);
});

///if ($(.dropdown-menu).height(){
$('.dropdown').mouseout(function(){
    $('.dropdown-menu').stop().slideUp(250);
});
});
 ///   })
</script>
</body>
</html>

CSS：

*{
    margin: 0;
    padding: 0;
}

/* Top nav syling */
.navbar-default{
    background-color: rgb(54, 135, 2);
    font-size: 120%;
}

/*Main display styling */

.jumbotron{
    height: 400px;
    background: url("../images/bg.jpg");
    background-size: cover;
    background-position: 50% 50%;
    width: 96%;
    border-bottom: 5px solid rgb(79, 201, 2);
    border-top: 5px solid rgb(79, 201,2);
    border-radius: 5px;
    position: relative;
    left: 50%;
    transform: translateX(-50%);
}

/*Navbar font coloring */
.nav.navbar-nav li a {
    color: white;
}

/* Centers content vertically */
.vert-center{
    position: relative;
    top: 50%;
    transform: translateY(-50%);
}

/*Styles partially transparent background within jumbotron class */
.transparent{
    background: rgba(190, 200, 216,.5);
    display: inline-block;
    padding-left: 20px;
    padding-right: 20px;
    border-radius: 5px;
    border-left: 4px solid rgb(79, 201, 2);
    border-right: 4px solid rgb(79, 201, 2);
    width: 60%;
}

/*Padding around desc within jumbotron */
#heading-desc {
    padding-top: 15px;
    padding-bottom: 15px;
}

/*Padding around title within jumbotron */
#heading-title{
    padding-top: 15px;
}

/* Bootstrap menu created using bootstrapdesigntools.com */
#custom-bootstrap-menu.navbar-default .navbar-brand {
    color: rgba(255, 255, 255, 1);
}

#custom-bootstrap-menu.navbar-default {
    font-size: 16px;
    background-color: rgba(54, 135, 2, 1);
    background: -webkit-linear-gradient(top, rgba(47, 196, 116, 1) 0%, rgba(54, 135, 2, 1) 100%);
    background: linear-gradient(to bottom, rgba(47, 196, 116, 1) 0%, rgba(54, 135, 2, 1) 100%);
    border-width: 1px;
    border-radius: 4px;
}

#custom-bootstrap-menu.navbar-default .navbar-nav>li>a {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(248, 248, 248, 0);
}
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a:focus {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(90, 224, 4, 1);
}

#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:focus {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(68, 168, 5, 1);
}

#custom-bootstrap-menu.navbar-default .navbar-toggle {
    border-color: #44a805;
}

/*Styling of icons */
.size{
    font-size: 60px;
    padding-top: 15px;
}

/*Outline surrounding three columns including icons */
.outline {
    border-left: 2px solid rgb(79, 201, 2);
    border-right: 2px solid rgb(79, 201, 2);
}
.navbar-bottom {
    background-color: rgba(222, 223, 224, 1);
    background: -webkit-linear-gradient(top, rgba(249, 249, 249, 1) 0%, rgba(222, 223, 224, 1) 100%);
    background: linear-gradient(to bottom, rgba(249, 249, 249, 1) 0%, rgba(222, 223, 224, 1) 100%);
    margin: 0;
    padding-top: 2px;
    margin-top: 90px;
}
.btn-format {
    display: block;
    width: 40%;
    left: 50%;
    height: 6%;
    border-radius: 3px;
    margin-top: 3px;
}
.horizontal-center{
    margin: 0 auto;
    width: 100px;
}
}
.footer-heading {
    font-size: 150px;
    margin-top: 2px;
    margin-bottom: 7px;
}
footer-title-pad {
    padding-top: 2px;
}


#custom-bootstrap-menu.navbar-default .navbar-brand {
    color: rgba(255, 255, 255, 1);
}
#custom-bootstrap-menu.navbar-default {
    font-size: 15px;
    background-color: rgba(47, 196, 116, 1);
    background: -webkit-linear-gradient(top, rgba(54, 135, 2, 1) 0%, rgba(47, 196, 116, 1) 100%);
    background: linear-gradient(to bottom, rgba(54, 135, 2, 1) 0%, rgba(47, 196, 116, 1) 100%);
    border-width: 1px;
    border-radius: 4px;
}
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(248, 248, 248, 0);
}
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a:focus {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(68, 229, 74, 1);
}
/*Styles active tab of top menu bar */
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:focus {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(57, 145, 3, 1));
    background: -webkit-linear-gradient(top, rgba(54, 135, 2, 1) 0%, rgba(57, 145, 3, 1) 100%);
    background: linear-gradient(to bottom, rgba(54, 135, 2, 1) 0%, rgba(57, 145, 3, 1) 100%);
}
#custom-bootstrap-menu.navbar-default .navbar-toggle {
    border-color: #42a503;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle:hover,
#custom-bootstrap-menu.navbar-default .navbar-toggle:focus {

    background-color: #42a503;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle .icon-bar {
    background-color: #42a503;
}

#custom-bootstrap-menu.navbar-default .navbar-toggle:hover .icon-bar,
#custom-bootstrap-menu.navbar-default .navbar-toggle:focus .icon-bar {
    background-color: #2fc474;
}
.navbar-bottom button {
  margin: auto;
}
.footer-bottom{
    margin-bottom: 7px;
}
.footer-top {
    margin-top: 2px;
}
/*Upper outline on bottom navigation bar*/
.outline-above {
    border-top: 1px solid rgb(79, 201,2);
}
/*Spacing between buttons in footer, error- needs more efficient  class */
#button-margin-top1 {
    margin-top: 8px;
}
#button-margin-top2 {
    margin-top: 8px;
}
#button-margin-top3 {
    margin-top: 8px;
}
/*dropdown menu background color */
.dropdown-menu{
    background-color: rgba(47, 196, 116, 1);
    background: -webkit-linear-gradient(top, rgba(67, 171, 3, .93) 0%, rgba(47, 196, 116, .93) 100%);
    background: linear-gradient(to bottom, rgba(67, 171, 3, .93) 0%, rgba(47, 196, 116, .93) 100%);
}
/*Dropdown menu on hover instead of click unless screen has been resized */
@media (min-width: 979px){
ul.nav li.dropdown:hover > ul.dropdown-menu {
    display: block;
    }
}
#custom-bootstrap-menu.navbar-default .dropdown-menu>li>a:hover,
#custom-bootstrap-menu.navbar-default .dropdown-menu>li>a:focus{
    background-color: rgba(68, 229, 74, 1);
}
/*Changes dropdown menu icon on screen resize */
.navbar-toggle, .icon-bar {
    background-color: rgba(44, 226, 50, 1);
}
.dropdown>a {
  display: block;
}

JQuery:

<script>
$(function(){
$('.dropdown').hover(function(){
    $('.dropdown-menu').slideDown(750);
});

///if ($(.dropdown-menu).height(){
$('.dropdown').mouseout(function(){
    $('.dropdown-menu').slideUp(750);
});
});
 ///   })
</script>

【问题讨论】：

标签： javascript jquery html css twitter-bootstrap

【解决方案1】：

问题是每次你悬停在动画上和离开时都会排队几次，这就是为什么你会看到重复的上下运动。像这样在动画前加一个stop()

$('.dropdown-menu').stop().slideUp(750);

您也需要为 slideUp 执行此操作

你可以看到这一切的行动 Here.

我建议将下拉菜单设置为文本显示块，并可能增加填充，因为它真的很容易取消悬停。

【讨论】：

谢谢！我如何将下拉菜单变成文本显示块？还有一种方法可以使鼠标悬停也适用于下拉菜单和按钮吗？是否类似于 css 选择多个元素，如 $('.class1','.class2')
您只需在 css 中设置 .dropdown a 的样式，我在示例中已经完成了它，就可以在顶部看到它。至于mouseout，我认为您可以单独应用它，但不能100％确定。如果答案有任何帮助，请务必接受它作为正确答案，以便其他人知道它解决了问题:)
添加停止后，它仍然不使用第一次鼠标悬停时的动画。我看不出它是如何在你的代码中完成的。我会在第一次鼠标悬停时将其标记为正确，谢谢您的帮助！