效果

预期效果

 //避免分页被截断
    async outPutPdfFn (id, title) {
      const _t = this;
      const A4_WIDTH = 592.28;
      const A4_HEIGHT = 841.89;
      // dom的id。
      let target = document.getElementById('pdf');
      let pageHeight = target.scrollWidth / A4_WIDTH * A4_HEIGHT;
      // 获取分割dom，此处为class类名为item的dom
      let lableListID = document.getElementsByClassName('item');
      // 进行分割操作，当dom内容已超出a4的高度，则将该dom前插入一个空dom，把他挤下去，分割
      for (let i = 0; i < lableListID.length; i++) {
        const currentItem = lableListID[i];
        let elToTop = document.getElementById('title').offsetTop + currentItem.offsetTop
        if (elToTop + currentItem.offsetHeight > pageHeight && elToTop < pageHeight) {
          let divParent = currentItem.parentNode; // 获取该div的父节点
          let newNode = document.createElement('div');
          newNode.className = 'emptyDiv';
          newNode.style.height = 8 + 'px';
          newNode.style.width = '100%';
          divParent.insertBefore(newNode, currentItem);
        }
      }
      await _t.$nextTick();
      _t.getPdf({
        id,
        title,
        backgroundColor: '#fff'
      }).then(base64 => {
        uni.postMessage({
          data: {
            pb: base64,
            name: title
          }
        })
        _t.navigateBack();
      })
    },