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>

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 >

你根本不需要JavaScript;只需设置title属性:

<div title="Hello, World!">
  <label>Name</label>
  <input type="text"/>
</div>

请注意，工具提示的可视化表示依赖于浏览器/操作系统，因此它可能会逐渐消失，也可能不会。然而，这是实现工具提示的语义方式，它可以正确地与屏幕阅读器等辅助软件一起工作。

在堆栈片段中的演示

<div title="Hello, World!"> < >标签名称> < /标签 < input type = " text " / > < / div >

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)

工具提示定位纯css

div { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); -ms-transform: translate(-50%, -50%); /* IE 9 */ -webkit-transform: translate(-50%, -50%); /* Chrome, Safari, Opera */ text-align: center; } .tooltip { position: relative; display: inline-block; border-bottom: 1px dotted black; } .tooltip .tooltiptext { visibility: hidden; width: 120px; background-color: black; color: #fff; //text-align: center; border-radius: 6px; padding: 5px 0; /* Position the tooltip */ position: absolute; z-index: 1; } .tooltip:hover .tooltiptext { visibility: visible; } .toolLeft { top: -5px; right: 105%; } .toolRight { top: -5px; left: 105%; } .toolTop { bottom: 100%; left: 50%; margin-left: -60px; } .toolBottom { top: 100%; left: 50%; margin-left: -60px; } <div> <div class="tooltip">Top <span class="tooltiptext toolTop">Tooltip text</span></div><br /> <div class="tooltip">Left <span class="tooltiptext toolLeft">Tooltip text</span></div><br /> <div class="tooltip">Right <span class="tooltiptext toolRight">Tooltip text</span></div><br /> <div class="tooltip">Bottom <span class="tooltiptext toolBottom">Tooltip text</span></div><br /> </div>

我开发了三种类型的褪色效果:

/* setup tooltips */ .tooltip { position: relative; } .tooltip:before, .tooltip:after { display: block; opacity: 0; pointer-events: none; position: absolute; } .tooltip:after { border-right: 6px solid transparent; border-bottom: 6px solid rgba(0,0,0,.75); border-left: 6px solid transparent; content: ''; height: 0; top: 20px; left: 20px; width: 0; } .tooltip:before { background: rgba(0,0,0,.75); border-radius: 2px; color: #fff; content: attr(data-title); font-size: 14px; padding: 6px 10px; top: 26px; white-space: nowrap; } /* the animations */ /* fade */ .tooltip.fade:after, .tooltip.fade:before { transform: translate3d(0,-10px,0); transition: all .15s ease-in-out; } .tooltip.fade:hover:after, .tooltip.fade:hover:before { opacity: 1; transform: translate3d(0,0,0); } /* expand */ .tooltip.expand:before { transform: scale3d(.2,.2,1); transition: all .2s ease-in-out; } .tooltip.expand:after { transform: translate3d(0,6px,0); transition: all .1s ease-in-out; } .tooltip.expand:hover:before, .tooltip.expand:hover:after { opacity: 1; transform: scale3d(1,1,1); } .tooltip.expand:hover:after { transition: all .2s .1s ease-in-out; } /* swing */ .tooltip.swing:before, .tooltip.swing:after { transform: translate3d(0,30px,0) rotate3d(0,0,1,60deg); transform-origin: 0 0; transition: transform .15s ease-in-out, opacity .2s; } .tooltip.swing:after { transform: translate3d(0,60px,0); transition: transform .15s ease-in-out, opacity .2s; } .tooltip.swing:hover:before, .tooltip.swing:hover:after { opacity: 1; transform: translate3d(0,0,0) rotate3d(1,1,1,0deg); } /* basic styling: has nothing to do with tooltips: */ h1 { padding-left: 50px; } ul { margin-bottom: 40px; } li { cursor: pointer; display: inline-block; padding: 0 10px; } <h1>FADE</h1> <div class="tooltip fade" data-title="Hypertext Markup Language"> <label>Name</label> <input type="text"/> </div> <h1>EXPAND</h1> <div class="tooltip expand" data-title="Hypertext Markup Language"> <label>Name</label> <input type="text"/> </div> <h1>SWING</h1> <div class="tooltip swing" data-title="Hypertext Markup Language"> <label>Name</label> <input type="text"/> </div>