设定文字行数 末尾加 查看全部

<div id='desc'</div>

// 描述
#desc{
    margin-top: 20px;
    font-family: PingFangSC-Regular;
    font-size: 16px;
    color: #5C5E66;
    // letter-spacing: 0;
    line-height: 22px;
    100%;
    height:110px;
    overflow:auto;
}

 {

    const el = document.getElementById('desc');
    const s = el.textContent;
    const n = el.offsetHeight;

    for (let i = 0; i < s.length; i++) {
      el.innerHTML = s.substr(0, i);
      if (n < el.scrollHeight) {
        el.style.overflow = 'hidden';
        el.innerHTML = s.substr(0, i - 8) + '... <span id="all">查看全部</span>';
        break;
      }
    }

    el.onclick = function (e)
    {

      if (el.style.overflow === 'hidden') {
        el.innerHTML = s;
        el.style.overflow = 'auto';
        el.style.height = 'auto';
      } else {
        for (let i = 0; i < s.length; i++) {
          el.innerHTML = s.substr(0, i);
          if (n < el.scrollHeight) {
            el.style.overflow = 'hidden';
            el.style.height = '110px';
            el.innerHTML = s.substr(0, i - 8) + '... <span id="all" >查看全部</span>';

            break;
          }
        }
      }
    };

  }