我的版本是

.tooltip{
display: inline;
position: relative; /** very important set to relative*/
}

.tooltip:hover:after{
background: #333;
background: rgba(0,0,0,.8);
border-radius: 5px;
bottom: 26px;
color: #fff;
content: attr(title); /**extract the content from the title */
left: 20%;
padding: 5px 15px;
position: absolute;
z-index: 98;
width: 220px;
}

.tooltip:hover:before{
border: solid;
border-color: #333 transparent;
border-width: 6px 6px 0 6px;
bottom: 20px;
content: "";
left: 50%;
position: absolute;
z-index: 99;
}

然后是HTML

<div title="This is some information for our tooltip." class="tooltip">bar </div>

我做了一些事情，应该能够适应一个div以及。

HTML

<td>
    <%# (Eval("Name").ToString().Length > 65) ? Eval("Name").ToString().Substring(0, 60) + "..." : Eval("Name")%>
    <span class="showonhover">
        <a href="#"><%# (Eval("Name").ToString().Length > 65) ? "More" : "" %></a>
        <span class="hovertext">
            <%# Eval("Name") %>
        </span>
    </span>
</td>

CSS

.showonhover .hovertext { display: none;}
.showonhover:hover .hovertext {display: inline;}
a.viewdescription {color:#999;}
a.viewdescription:hover {background-color:#999; color: White;}
.hovertext {position:absolute;z-index:1000;border:1px solid #ffd971;background-color:#fffdce;padding:11px;width:150px;font-size: 0.75em;}

要了解更深入的讨论，请参阅我的文章:

一个简单的格式化工具提示文本悬停

下面是一个简单的工具提示实现，它可以考虑鼠标的位置以及窗口的高度和宽度:

function showTooltip(e) { var tooltip = e.target.classList.contains("tooltip") ? e.target : e.target.querySelector(":scope .tooltip"); tooltip.style.left = (e.pageX + tooltip.clientWidth + 10 < document.body.clientWidth) ? (e.pageX + 10 + "px") : (document.body.clientWidth + 5 - tooltip.clientWidth + "px"); tooltip.style.top = (e.pageY + tooltip.clientHeight + 10 < document.body.clientHeight) ? (e.pageY + 10 + "px") : (document.body.clientHeight + 5 - tooltip.clientHeight + "px"); } var tooltips = document.querySelectorAll('.couponcode'); for(var i = 0; i < tooltips.length; i++) { tooltips[i].addEventListener('mousemove', showTooltip); } .couponcode { color: red; cursor: pointer; } .couponcode:hover .tooltip { display: block; } .tooltip { position: absolute; white-space: nowrap; display: none; background: #ffffcc; border: 1px solid black; padding: 5px; z-index: 1000; color: black; } Lorem ipsum dolor sit amet, <span class="couponcode">consectetur adipiscing<span class="tooltip">This is a tooltip</span></span> elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in <span class="couponcode">reprehenderit<span class="tooltip">This is another tooltip</span></span> in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est <span class="couponcode">laborum<span class="tooltip">This is yet another tooltip</span></span>.

(也可以参看这把小提琴)

您可以使用数据属性，伪元素和内容创建自定义CSS工具提示:attr()等。

http://jsfiddle.net/clintioo/gLeydk0k/11/

<div data-tooltip="This is my tooltip">
    <label>Name</label>
    <input type="text" />
</div>

.

div:hover:before {
    content: attr(data-tooltip);
    position: absolute;
    padding: 5px 10px;
    margin: -3px 0 0 180px;
    background: orange;
    color: white;
    border-radius: 3px;
}

div:hover:after {
    content: '';
    position: absolute;
    margin: 6px 0 0 3px;
    width: 0;
    height: 0;
    border-top: 5px solid transparent;
    border-right: 10px solid orange;
    border-bottom: 5px solid transparent;
}

input[type="text"] {
    width: 125px;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}

试试这个。你可以这样做，只有css和我只添加了数据标题属性的工具提示。

.tooltip { 位置:相对; 显示:inline-block; ｝ .tooltip [data-title]:徘徊:{后 内容:attr (data-title); 填充:4px 8px; 颜色:# fff; 位置:绝对的; 左:0; 上图:110%; 空白:nowrap;} border - radius: 5 px; 背景:# 000; ｝ <div data-title="My tooltip" class="tooltip"> < >标签名称> < /标签 < input type = " text " / > < / div >

它可以只用CSS，不需要javascript

运行演示

[data-tooltip]:before { /* needed - do not touch */ content: attr(data-tooltip); position: absolute; opacity: 0; /* customizable */ transition: all 0.15s ease; padding: 10px; color: #333; border-radius: 10px; box-shadow: 2px 2px 1px silver; } [data-tooltip]:hover:before { /* needed - do not touch */ opacity: 1; /* customizable */ background: yellow; margin-top: -50px; margin-left: 20px; } [data-tooltip]:not([data-tooltip-persistent]):before { pointer-events: none; } /* FOR TEST PURPOSES ONLY */ div { border: 1px solid silver; background: #ddd; margin: 20px; padding: 10px; } <div>Standard div, no tooltip here</div> <div data-tooltip="Hi, I'm a tooltip. Pretty easy uh ? ;)">Div with standard tooltip. Hover me to see the tooltip. <br/>Hovering the tooltip doesn't matter: <br/>if you hover out of my boundaries, the tooltip will disappear.</div> <div data-tooltip="Hi, I'm a persistent tooltip. I won't disappear when hovering me even if out of my parent boundaries. I'll also prevent other tooltips to fire :)" data-tooltip-persistent="foo">Div with persistent tooltip. Hover me to see the tooltip. <br/>The tooltip won't expire until you hover on me OR it.</div>

Apply a custom HTML attribute, eg. data-tooltip="bla bla" to your object (div or whatever): <div data-tooltip="bla bla"> something here </div> Define the :before pseudoelement of each [data-tooltip] object to be transparent, absolutely positioned and with data-tooltip="" value as content: [data-tooltip]:before { position : absolute; content : attr(data-tooltip); opacity : 0; } Define :hover:before hovering state of each [data-tooltip] to make it visible: [data-tooltip]:hover:before { opacity : 1; } Apply your styles (color, size, position etc) to the tooltip object; end of the story.

在演示中，我定义了另一个规则来指定当鼠标悬停在工具提示上但不在父工具提示上时，工具提示是否必须消失，使用另一个自定义属性data-tooltip-persistent和一个简单的规则:

[data-tooltip]:not([data-tooltip-persistent]):before {
    pointer-events: none;
}

注1:浏览器的覆盖范围很广，但可以考虑为旧的IE使用javascript回退(如果需要的话)。

注2:一种增强可能是添加一些javascript来计算鼠标位置，并通过改变应用于它的类将其添加到伪元素中。