vue 中 element-ui table合并上下两行相同数据单元格

 <el-table
 :header-cell-style="{background:'#6d7f93',color:'white'}"
 :data="ptableDate"
 align="center"
 border
 v-loading="loading"
 :height="tableHeight"
 :span-method="objectOneMethod"
 >
 <el-table-column align="center" show-overflow-tooltip prop="projName" ></el-table-column>
 <el-table-column align="center" show-overflow-tooltip prop="dirtySection" ></el-table-column>
 <el-table-column align="center" show-overflow-tooltip prop="towerNumber" ></el-table-column>
 <el-table-column align="center" show-overflow-tooltip prop="inclination" ></el-table-column>
 </el-table>

objectOneMethod({ row, column, rowIndex, columnIndex }) {
 if (columnIndex === 0) {
 const _row = this.setTable(this.ptableDate).one[rowIndex];
 const _col = _row > 0 ? 1 : 0;
 return {
 rowspan: _row,
 colspan: _col
 };
 }
 if (columnIndex === 1 ) {
 const _row = this.setTable(this.ptableDate).two[rowIndex];
 const _col = _row > 0 ? 1 : 0;
 return {
 rowspan: _row,
 colspan: _col
 };
 }
 },
 setTable(tableData) {
 let spanOneArr = [],
 spanTwoArr = [],
 concatOne = 0,
 concatTwo = 0;
 tableData.forEach((item, index) => {
 if (index === 0) {
 spanOneArr.push(1);
 spanTwoArr.push(1);
 } else {
 if (item.projName === tableData[index - 1].projName) {
 //第一列需合并相同内容的判断条件
 spanOneArr[concatOne] += 1;
 spanOneArr.push(0);
 } else {
 spanOneArr.push(1);
 concatOne = index;
 }
 if (item.dirtySection === tableData[index - 1].dirtySection) {
 //第二列和需合并相同内容的判断条件
 spanTwoArr[concatTwo] += 1;
 spanTwoArr.push(0);
 } else {
 spanTwoArr.push(1);
 concatTwo = index;
 }
 }
 });
 return {
 one: spanOneArr,
 two: spanTwoArr
 };
 },

arraySpanMethod({ row, column, rowIndex, columnIndex }) {
// 只合并区域位置
  //columnIndex 横的第一列
  //rowIndex 竖的数组的length % 3 ==0 合并单元格
 if (columnIndex === 0) { //如果是第一行
if (rowIndex % 3 === 0) {//如果是 数组长度 % 3 ==0
return {
rowspan: 3,
colspan: 1
};
} else {
return {
rowspan: 0,
colspan: 0
};
}
}
},