如何将下拉菜单与按钮对齐

Question

我有一个下拉菜单与html, css和一些js。它工作得很好，我还添加了一些动画。现在我想把它对齐在点击我按钮下面!我一直在寻找周围的堆栈，并尝试浮动和对齐，但我不能。对不起，我是新手，有人能帮我吗?

感谢您的回复，谢谢。

function myFunction() {
var x = document.getElementById("Demo");
if (x.className.indexOf("w3-show") == -1) {
x.className += " w3-show";
} else { 
x.className += " w3-hide";
setTimeout(function(){
x.className = x.className.replace(" w3-show", "");
x.className = x.className.replace(" w3-hide", "");

},500)
}
}

/*Items menu*/
.user_menu_item {
display: flex;
align-items: center;
}
.user_menu_item:hover {
background: whitesmoke;
border-left: 4px solid blue;
transition: 0.3s;
}
.user_menu_item:not(:hover) {
transition: 0.3s;
}
.user_menu_item > a {
display: flex;
align-items: center;
padding: 12px 10px 12px 10px;
width: 100%;
font-size: 14px;
color: #75777D;
}
.w3-container {
position: absolute;
top: 15%;
}
.w3-dropdown-click {
display: flex;
position: relative;
}
.w3-dropdown-content {
display: none;
background-color: whitesmoke;
min-width: 160px;
overflow: hidden;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
position:relative;

animation:animateFromBottom 0.6s
}
@keyframes animateFromBottom {
from{bottom:-50px;opacity:0} to{bottom:0;opacity:1}
}
@keyframes animateToBottom {
from{bottom:0;opacity:1} to{bottom:-50px;opacity:0}
}
.w3-bar-block .w3-bar-item {
width:100%;
display:block;
padding:8px 16px;
text-align:left;
border:none;
white-space:normal;
float:none;
outline:0
}
.w3-show-block,.w3-show {
display:block!important
}
.w3-dropdown-content.w3-hide {
animation:animateToBottom 0.6s
}
.w3-button {
float: right;
}

<button onclick="myFunction()" class="w3-button">Click Me!</button> 
<div class="w3-container">
<div class="w3-dropdown-click">


<div id="Demo" class="w3-dropdown-content w3-bar-block w3-border">
<div class="user_menu_item">
<a href="/account">
<span class="link_text">Dashboard</span>
</a>
</div>

<div class="user_menu_item">
<a href="ordini">
<span class="link_text">I miei ordini</span>
</a>
</div>

<div class="user_menu_item">
<a href="libreria">
<span class="link_text">Downloads</span>
</a>
</div>

<div class="user_menu_item">
<a href="impostazioni">
<span class="link_text">Impostazioni</span>
</a>
</div>

<div class="user_menu_item">
<a href="wp-login.php?action=logout">
<span class="link_text">Logout</span>
</a>
</div>
</div>
</div>
</div>

Answer 1

你可以创建一个容器div来放置菜单和按钮本身，然后给这个容器绝对定位属性，就像你对菜单所做的那样。你必须调整你的菜单位置，所以当它出现时，它不会重叠按钮，但我在代码中照顾到这一点。此外，如果你想让按钮和菜单在绝对的右边，而不是偏移和溢出屏幕的右侧，你需要修改菜单本身的位置。

见:https://developer.mozilla.org/pt-BR/docs/Web/CSS/position

function myFunction() {
var x = document.getElementById("Demo");
if (x.className.indexOf("w3-show") == -1) {
x.className += " w3-show";
} else {
x.className += " w3-hide";
setTimeout(function() {
x.className = x.className.replace(" w3-show", "");
x.className = x.className.replace(" w3-hide", "");
}, 500)
}
}

.container {
display: block;
margin: 0 0;
position: absolute;
top: 10px;
right: 0px;
}
/*Items menu*/
.user_menu_item {
display: flex;
align-items: center;
}
.user_menu_item:hover {
background: whitesmoke;
border-left: 4px solid blue;
transition: 0.3s;
}
.user_menu_item:not(:hover) {
transition: 0.3s;
}
.user_menu_item>a {
display: flex;
align-items: center;
padding: 12px 10px 12px 10px;
width: 100%;
font-size: 14px;
color: #75777D;
}
.w3-container {
position: absolute;
top: 25px;
right: 0px;
}
.w3-dropdown-click {
display: flex;
position: relative;
}
.w3-dropdown-content {
display: none;
background-color: whitesmoke;
min-width: 160px;
overflow: hidden;
box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
z-index: 1;
position: relative;
animation: animateFromBottom 0.6s
}
@keyframes animateFromBottom {
from {
bottom: -50px;
opacity: 0
}
to {
bottom: 0;
opacity: 1
}
}
@keyframes animateToBottom {
from {
bottom: 0;
opacity: 1
}
to {
bottom: -50px;
opacity: 0
}
}
.w3-bar-block .w3-bar-item {
width: 100%;
display: block;
padding: 8px 16px;
text-align: left;
border: none;
white-space: normal;
float: none;
outline: 0;
}
.w3-show-block,
.w3-show {
display: block !important
}
.w3-dropdown-content.w3-hide {
animation: animateToBottom 0.6s
}
.w3-button {
display: block;
}

<div class="container">
<button onclick="myFunction()" class="w3-button">Click Me!</button>
<div class="w3-container">
<div class="w3-dropdown-click">

<div id="Demo" class="w3-dropdown-content w3-bar-block w3-border">
<div class="user_menu_item">
<a href="/account">
<span class="link_text">Dashboard</span>
</a>
</div>
<div class="user_menu_item">
<a href="ordini">
<span class="link_text">I miei ordini</span>
</a>
</div>
<div class="user_menu_item">
<a href="libreria">
<span class="link_text">Downloads</span>
</a>
</div>
<div class="user_menu_item">
<a href="impostazioni">
<span class="link_text">Impostazioni</span>
</a>
</div>
<div class="user_menu_item">
<a href="wp-login.php?action=logout">
<span class="link_text">Logout</span>
</a>
</div>
</div>
</div>
</div>
</div>

Answer 2

将弹出窗口和按钮添加到同一父元素中，并设置其相对位置，然后将弹出窗口值的顶部设置为静态值(height of btn)

function myFunction() {
var x = document.getElementById("Demo");
if (x.className.indexOf("w3-show") == -1) {
x.className += " w3-show";
} else {
x.className += " w3-hide";
setTimeout(function() {
x.className = x.className.replace(" w3-show", "");
x.className = x.className.replace(" w3-hide", "");
}, 500);
}
}

.main_container {
position: relative;
}

/*Items menu*/
.user_menu_item {
display: flex;
align-items: center;
}
.user_menu_item:hover {
background: whitesmoke;
border-left: 4px solid blue;
transition: 0.3s;
}
.user_menu_item:not(:hover) {
transition: 0.3s;
}
.user_menu_item>a {
display: flex;
align-items: center;
padding: 12px 10px 12px 10px;
width: 100%;
font-size: 14px;
color: #75777d;
}
.w3-container {
position: absolute;
right: 0;
top: 25px;
}
.w3-dropdown-click {
display: flex;
position: relative;
}
.w3-dropdown-content {
display: none;
background-color: whitesmoke;
min-width: 160px;
overflow: hidden;
box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
z-index: 1;
position: relative;
animation: animateFromBottom 0.6s;
}
@keyframes animateFromBottom {
from {
bottom: -50px;
opacity: 0;
}
to {
bottom: 0;
opacity: 1;
}
}
@keyframes animateToBottom {
from {
bottom: 0;
opacity: 1;
}
to {
bottom: -50px;
opacity: 0;
}
}
.w3-bar-block .w3-bar-item {
width: 100%;
display: block;
padding: 8px 16px;
text-align: left;
border: none;
white-space: normal;
float: none;
outline: 0;
}
.w3-show-block,
.w3-show {
display: block !important;
}
.w3-dropdown-content.w3-hide {
animation: animateToBottom 0.6s;
}
.w3-button {
float: right;
}

<div class="main_container">
<button onclick="myFunction()" class="w3-button">Click Me!</button>
<div class="w3-container">
<div class="w3-dropdown-click">
<div id="Demo" class="w3-dropdown-content w3-bar-block w3-border">
<div class="user_menu_item">
<a href="/account">
<span class="link_text">Dashboard</span>
</a>
</div>
<div class="user_menu_item">
<a href="ordini">
<span class="link_text">I miei ordini</span>
</a>
</div>
<div class="user_menu_item">
<a href="libreria">
<span class="link_text">Downloads</span>
</a>
</div>
<div class="user_menu_item">
<a href="impostazioni">
<span class="link_text">Impostazioni</span>
</a>
</div>
<div class="user_menu_item">
<a href="wp-login.php?action=logout">
<span class="link_text">Logout</span>
</a>
</div>
</div>
</div>
</div>
</div>