如何将无序列表居中？

Question

我有一个由<ul>和<li>创建的家谱，但我已尝试过所有内容，但我似乎无法将整棵树正确居中。

我尝试将.tree居中，并将.tree包裹在另一个div中，但似乎没有任何效果！

http://jsfiddle.net/V8H6T/4/

HTML：

<div class="tree">
    <ul>
        <li>
            <a href="chairman"><span class="accent">Chairman / Owner</span><p>Name</p></a>



            <ul>
                <li>
                    <a href="financemanager"><span class="accent">Finance &<br>
                    Managing Director</span><span>Name</span></a>

                    <ul>
                        <li><a href="financeteam"><span class="accent">Finance
                        Team</span> <span>Name</span><br></a></li>

                        <li><a href="salesdirector"><span class="accent">Sales
                        Director</span><span>Name</span></a></li>
                    </ul>
                </li>
            </ul>
        </li>
    </ul>
</div>

CSS：

body {
    width:100%;
}

* {margin: 0; padding: 0;}

ul {
    line-height:20px;
}

.tree ul {
    padding-top: 20px; position: relative;

    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}

.tree li {
    float: left; text-align: center;
    list-style-type: none;
    position: relative;
    padding: 20px 5px 0 5px;

    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}

/*We will use ::before and ::after to draw the connectors*/

.tree li::before, .tree li::after{
    content: '';
    position: absolute; top: 0; right: 50%;
    border-top: 1px solid #ccc;
    width: 50%; height: 20px;
}
.tree li::after{
    right: auto; left: 50%;
    border-left: 1px solid #ccc;
}

/*We need to remove left-right connectors from elements without 
any siblings*/
.tree li:only-child::after, .tree li:only-child::before {
    display: none;
}

/*Remove space from the top of single children*/
.tree li:only-child{ padding-top: 0;}

/*Remove left connector from first child and 
right connector from last child*/
.tree li:first-child::before, .tree li:last-child::after{
    border: 0 none;
}

/*Adding back the vertical connector to the last nodes*/

.tree li:last-child::before{
    border-right: 1px solid #ccc;
    border-radius: 0 0px 0 0;
    -webkit-border-radius: 0 0px 0 0;
    -moz-border-radius: 0 0px 0 0;
}

.tree li:first-child::after{
    border-radius: 0px 0 0 0;
    -webkit-border-radius: 0px 0 0 0;
    -moz-border-radius: 0px 0 0 0;
}

/*Time to add downward connectors from parents*/
.tree ul ul::before{
    content: '';
    position: absolute; top: 0; left: 50%;
    border-left: 1px solid #ccc;
    width: 0; height: 20px;
}

.tree li a{
    border: 1px solid #ccc;
    padding: 5px 10px;
    text-decoration: none;
    color: #666;
    font-family: arial, verdana, tahoma;
    font-size: 13px;
    display: inline-block;

    border-radius: 0px;
    -webkit-border-radius: 0px;
    -moz-border-radius: 0px;

    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}

/*Time for some hover effects*/
/*We will apply the hover effect the the lineage of the element also*/
.tree li a:hover, .tree li a:hover+ul li a {
    background: #E9E9E9; color: black; border: 1px solid #94a0b4;
}
/*Connector styles on hover*/
.tree li a:hover+ul li::after, 
.tree li a:hover+ul li::before, 
.tree li a:hover+ul::before, 
.tree li a:hover+ul ul::before{
    border-color:#06C;
}

span.accent{
    background-color: #113963;
    display: block;
    margin: -5px -10px 5px;
    padding: 5px;
    color: white;
    font-weight:bold;
}

Answer 1

你在找这个吗？

Demo

.tree{
    width:250px;
    margin:0 auto;
}

Answer 2

这是一种方法。

在div.wrap附近添加包装div.tree：

<div class="wrap">
    <div class="tree">
        <ul>
            <li> <a href="chairman"><span class="accent">Chairman / Owner</span></a>

                <p>Name</p>
                <ul>
                    <li> <a href="financemanager"><span class="accent">Finance &<br>
                    Managing Director</span><span>Name</span></a>

                        <ul>
                            <li><a href="financeteam"><span class="accent">Finance
                        Team</span> <span>Name</span><br></a>
                            </li>
                            <li><a href="salesdirector"><span class="accent">Sales
                        Director</span><span>Name</span></a>
                            </li>
                        </ul>
                    </li>
                </ul>
            </li>
        </ul>
    </div>
</div>

对于CSS，

.wrap {
    border: 1px dashed blue;
    text-align: center;
}
.tree {
    border: 1px dotted blue;
    display: inline-block;
}
.tree ul {
    padding-top: 20px;
    position: relative;
    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
    border: 1px dashed red;
    overflow: auto;
}

将display: inline-block应用于div.tree以获得最小宽度，然后使用text-align: center中的div.wrap获取水平居中。

我还将overflow: auto添加到.tree ul以包含其中的浮动元素 阻止格式化上下文。

请参阅演示：http://jsfiddle.net/audetwebdesign/8gBAV/

这种方法的优点是您不必指定.tree的宽度，这将使布局更灵活，更灵敏。

Answer 3

这是小提琴：FIDDLE

<div class="tree">
<ul>
    <li>
        <a href="chairman"><span class="accent">Chairman / Owner</span></a>

        <p>Name</p>

        <ul>
            <li>
                <a href="financemanager"><span class="accent">Finance &<br>
                Managing Director</span><span>Name</span></a>

                <ul>
                    <li><a href="financeteam"><span class="accent">Finance
                    Team</span> <span>Name</span><br></a></li>

                    <li><a href="salesdirector"><span class="accent">Sales
                    Director</span><span>Name</span></a></li>
                </ul>
            </li>
        </ul>
    </li>
</ul>

    body {
  position:absolute;
     width:300px;
     height:200px;
     z-index:15;
     top:50%;
     left:50%;
     margin:-100px 0 0 -150px;

}

* {margin: 0; padding: 0;}

ul {
    line-height:20px;
}

.tree ul {
    padding-top: 20px; position: relative;

    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}

.tree li {
    float: left; text-align: center;
    list-style-type: none;
    position: relative;
    padding: 20px 5px 0 5px;

    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}

/*We will use ::before and ::after to draw the connectors*/

.tree li::before, .tree li::after{
    content: '';
    position: absolute; top: 0; right: 50%;
    border-top: 1px solid #ccc;
    width: 50%; height: 20px;
}
.tree li::after{
    right: auto; left: 50%;
    border-left: 1px solid #ccc;
}

/*We need to remove left-right connectors from elements without 
any siblings*/
.tree li:only-child::after, .tree li:only-child::before {
    display: none;
}

/*Remove space from the top of single children*/
.tree li:only-child{ padding-top: 0;}

/*Remove left connector from first child and 
right connector from last child*/
.tree li:first-child::before, .tree li:last-child::after{
    border: 0 none;
}

/*Adding back the vertical connector to the last nodes*/

.tree li:last-child::before{
    border-right: 1px solid #ccc;
    border-radius: 0 0px 0 0;
    -webkit-border-radius: 0 0px 0 0;
    -moz-border-radius: 0 0px 0 0;
}

.tree li:first-child::after{
    border-radius: 0px 0 0 0;
    -webkit-border-radius: 0px 0 0 0;
    -moz-border-radius: 0px 0 0 0;
}

/*Time to add downward connectors from parents*/
.tree ul ul::before{
    content: '';
    position: absolute; top: 0; left: 50%;
    border-left: 1px solid #ccc;
    width: 0; height: 20px;
}

.tree li a{
    border: 1px solid #ccc;
    padding: 5px 10px;
    text-decoration: none;
    color: #666;
    font-family: arial, verdana, tahoma;
    font-size: 13px;
    display: inline-block;

    border-radius: 0px;
    -webkit-border-radius: 0px;
    -moz-border-radius: 0px;

    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}

/*Time for some hover effects*/
/*We will apply the hover effect the the lineage of the element also*/
.tree li a:hover, .tree li a:hover+ul li a {
    background: #E9E9E9; color: black; border: 1px solid #94a0b4;
}
/*Connector styles on hover*/
.tree li a:hover+ul li::after, 
.tree li a:hover+ul li::before, 
.tree li a:hover+ul::before, 
.tree li a:hover+ul ul::before{
    border-color:#06C;
}

span.accent{
    background-color: #113963;
    display: block;
    margin: -5px -10px 5px;
    padding: 5px;
    color: white;
    font-weight:bold;
}

Answer 4

.tree{
margin: auto 25%;
min-width:300px;
width:50%;

}

JSFiddle

min-width：300px 可防止在调整窗口大小时错误地放置树