单行文本溢出

效果：

html

 <div>
    你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！
 </div>

css:

  <style>
    div{
      width: 300px;
      border: 1px solid #ccc;
      overflow: hidden;
      white-space: nowrap;
      text-overflow: ellipsis;
    }
  </style>

多行文本溢出

方法一：基于高度截断

html代码：

<div>
    你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！
    你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！你好呀！
  </div>

css 代码：

<style>
    div{
      width: 300px;
      border: 1px solid #ccc;
      position: relative;
      overflow: hidden;
      height: 40px;
      line-height: 20px;
    }
    div::after{
      content: '...';
      position: absolute;
      bottom: 0;
      right: 0;
    }
  </style>

方法二：基础行数截断【纯CSS】

html同上

css 代码

<style>
    div{
      width: 300px;
      border: 1px solid #ccc;
      -webkit-line-clamp: 2;
      display: -webkit-box;
      -webkit-box-orient: vertical;
      overflow: hidden;
      text-overflow: ellipsis;
    }
  </style>

方法二：基础行数截断【JS实现】

css 代码

<style>
    p{
      width: 300px;
      border: 1px solid #ccc;
      position: relative;
      overflow: hidden;
      line-height: 20px;
    }
    
    .p-after::after {
      content: '...';
      position: absolute;
      bottom: 0;
      right: 0;
      background: -webkit-linear-gradient(left, transparent, #fff 50%);
      background: linear-gradient(to right, transparent, #fff 55%);
    }
  </style>

js 代码

<script>
    (function () {
      const divEl = document.getElementsByTagName('p')[0];
      var lineHeightPro = window.getComputedStyle(divEl).getPropertyValue('line-height');
      var lineHeight = lineHeightPro.substring(0, lineHeightPro.indexOf('p'));
      var heightPro = window.getComputedStyle(divEl).getPropertyValue('height');
      var height = heightPro.substring(0, heightPro.indexOf('p'));
      if ((parseInt(height) / parseInt(lineHeight)) > 3) {
        divEl.classList.add('p-after');
        divEl.style.height = '60px';
      } else {
        divEl.classList.remove('p-after');
      }
    })()
  </script>