function sumLabel(){

  const point = this;

  const points = point.points;

  const validPoints = points.filter( (point) => point.isVisible() );

  if(point == validPoints[validPoints.length - 1]){

    let value = 0;

    for(let i = 0; i < validPoints.length; i++){

      value += validPoints[i].value;

    }

    return "   合计"+value+"\n  "+this.value+"\n\n   ";

  } else {

    return this.value;

  }

}

效果

https://help.fanruan.com/finereport/doc-view-4372

看下这个链接

https://help.fanruan.com/finereport/doc-view-4372.html 

function sumLabel() {

    const point = this;

    const points = point.points;

    const validPoints = points.filter((point) => point.isVisible());

    if (point === validPoints[validPoints.length - 1]) {

        let value = 0;

        for (let i = 0; i < validPoints.length; i++) {

            value += validPoints[i].value;

        }

        // 使用HTML标签使value加粗和黑体显示，并放置在顶部

        return `<b style="font-weight:bold; color:white;">${value}</b>` + `` + this.value + ``;

    } else {

        return this.value;

    }

}