display: -webkit-box;
-webkit-line-clamp: 3;
-webkit-box-orient: vertical; 

点击这里查看更多信息

display: -webkit-box;
-webkit-line-clamp: 3;
-webkit-box-orient: vertical; 

点击这里查看更多信息

我一直在尝试，直到我成功地实现了接近这个的东西。但有几点需要注意:

It's not pure CSS; you have to add a few HTML elements. There's however no JavaScript required. The ellipsis is right-aligned on the last line. This means that if your text isn't right-aligned or justified, there may be a noticable gap between the last visible word and the ellipsis (depending on the length of the first hidden word). The space for the ellipsis is always reserved. This means that if the text fits in the box almost precisely, it may be unnecessarily truncated (the last word is hidden, although it technically wouldn't have to). Your text needs to have a fixed background color, since we're using colored rectangles to hide the ellipsis in cases where it's not needed.

我还应该注意，文本将在单词边界处断开，而不是字符边界处断开。这是有意为之(因为我认为这对较长的文本更好)，但因为它不同于text-overflow: ellipsis，所以我认为我应该提到它。

如果你可以接受这些警告，HTML看起来是这样的:

<div class="ellipsify">
    <div class="pre-dots"></div>
    <div class="dots">&hellip;</div>
    <!-- your text here -->
    <span class="hidedots1"></span>
    <div class="hidedots2"></div>
</div>

这是相应的CSS，以一个150像素宽的盒子为例，在白色背景上有三行文本。它假设你有一个CSS重置或类似的设置，在必要的地方将边距和填充设置为零。

/* the wrapper */
.ellipsify {
    font-size:12px;
    line-height:18px;
    height: 54px;       /* 3x line height */
    width: 150px;
    overflow: hidden;
    position: relative; /* so we're a positioning parent for the dot hiders */
    background: white;
}

/* Used to push down .dots. Can't use absolute positioning, since that
   would stop the floating. Can't use relative positioning, since that
   would cause floating in the wrong (namely: original) place. Can't 
   change height of #dots, since it would have the full width, and
   thus cause early wrapping on all lines. */
.pre-dots {
    float: right;
    height: 36px;  /* 2x line height (one less than visible lines) */
}

.dots {
    float: right; /* to make the text wrap around the dots */
    clear: right; /* to push us below (not next to) .pre-dots */
}

/* hides the dots if the text has *exactly* 3 lines */
.hidedots1 {
    background: white;
    width: 150px;
    height: 18px;       /* line height */
    position: absolute; /* otherwise, because of the width, it'll be wrapped */
}

/* hides the dots if the text has *less than* 3 lines */
.hidedots2 {
    background: white; 
    width: 150px;
    height: 54px;       /* 3x line height, to ensure hiding even if empty */
    position: absolute; /* ensures we're above the dots */
}

结果如下所示:

为了阐明它是如何工作的，下面是相同的图像，除了.hidedots1用红色突出显示，而.hidedots2用青色突出显示。当没有看不见的文本时，这些矩形隐藏了省略号:

在IE9, IE8(模拟)，Chrome, Firefox, Safari和Opera中测试。IE7不支持。

这里有一篇最近的css技巧文章讨论了这个问题。

上面文章中的一些解决方案(这里没有提到)是

1) -webkit-line-clamp和2)放置一个绝对定位的元素右下角淡出

这两种方法都假设有以下标记:

<div class="module"> /* Add line-clamp/fade class here*/
  <p>Text here</p>
</div>

用css

.module {
  width: 250px;
  overflow: hidden;
}

1) -webkit-line-clamp

线夹(..最多3行)

.line-clamp {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;  
  max-height: 3.6em; /* I needed this to get it to work */
}

2)淡出

假设您将行高设置为1.2em。如果我们想曝光 三行文本，我们可以设置容器的高度 3.6em (1.2em × 3).隐藏溢出将隐藏其余部分。

淡出小提琴

p
{
    margin:0;padding:0;
}
.module {
  width: 250px;
  overflow: hidden;
  border: 1px solid green;
  margin: 10px;
}

.fade {
  position: relative;
  height: 3.6em; /* exactly three lines */
}
.fade:after {
  content: "";
  text-align: right;
  position: absolute;
  bottom: 0;
  right: 0;
  width: 70%;
  height: 1.2em;
  background: linear-gradient(to right, rgba(255, 255, 255, 0), rgba(255, 255, 255, 1) 50%);
}

解决方案#3 -使用@supports的组合

我们可以使用@supports在webkit浏览器上应用webkit的线夹，并在其他浏览器上应用淡出。

@支持线钳与淡出回退小提琴

<div class="module line-clamp">
  <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p>
</div>

CSS

.module {
  width: 250px;
  overflow: hidden;
  border: 1px solid green;
  margin: 10px;
}

.line-clamp {
      position: relative;
      height: 3.6em; /* exactly three lines */
    }
.line-clamp:after {
      content: "";
      text-align: right;
      position: absolute;
      bottom: 0;
      right: 0;
      width: 70%;
      height: 1.2em;
      background: linear-gradient(to right, rgba(255, 255, 255, 0), rgba(255, 255, 255, 1) 50%);
 }

@supports (-webkit-line-clamp: 3) {
    .line-clamp {
        display: -webkit-box;
        -webkit-line-clamp: 3;
        -webkit-box-orient: vertical;  
        max-height:3.6em; /* I needed this to get it to work */
        height: auto;
    }
    .line-clamp:after {
        display: none;
    }
}

Javascript解决方案将更好

获取文本的行数 如果窗口调整大小或元素更改，则切换is-省略号类

getRowRects

getclientrects()是这样工作的

同一行中的每个矩形都有相同的顶部值，所以找出顶部值不同的矩形，就像这样

function getRowRects(element) {
    var rects = [],
        clientRects = element.getClientRects(),
        len = clientRects.length,
        clientRect, top, rectsLen, rect, i;

    for(i=0; i<len; i++) {
        has = false;
        rectsLen = rects.length;
        clientRect = clientRects[i];
        top = clientRect.top;
        while(rectsLen--) {
            rect = rects[rectsLen];
            if (rect.top == top) {
                has = true;
                break;
            }
        }
        if(has) {
            rect.right = rect.right > clientRect.right ? rect.right : clientRect.right;
            rect.width = rect.right - rect.left;
        }
        else {
            rects.push({
                top: clientRect.top,
                right: clientRect.right,
                bottom: clientRect.bottom,
                left: clientRect.left,
                width: clientRect.width,
                height: clientRect.height
            });
        }
    }
    return rects;
}

浮动…更多

像这样

检测窗口大小或元素改变

像这样

我发现了一个javascript技巧，但你必须使用字符串的长度。假设你想要3行宽250px，你可以计算每行的长度。

//get the total character length.
//Haha this might vary if you have a text with lots of "i" vs "w"
var totalLength = (width / yourFontSize) * yourNumberOfLines

//then ellipsify
function shorten(text, totalLength) {
    var ret = text;
    if (ret.length > totalLength) {
        ret = ret.substr(0, totalLength-3) + "...";
    }
    return ret;
}