el-table sorting

  <el-table-column
        align="center"
        label="排序">
        <template slot-scope="scope">
          <el-button
            size="mini"
            icon="el-icon-bottom"
            :disabled="scope.$index === tableData.length - 1"
            @click="moveDown(scope.$index, scope.row)"
          >
          </el-button>
          <el-button
            size="mini"
            icon="el-icon-top"
            :disabled="scope.$index === 0"
            @click="moveUp(scope.$index, scope.row)"
          >
          </el-button>
        </template>
      </el-table-column>



js
                // 上移
    moveUp(index, row) {
      if (index > 0) {
        const upDate = this.tableData[index - 1];
        this.tableData.splice(index - 1, 1);
        this.tableData.splice(index, 0, upDate);
       
      } else {
        alert("已经是第一条，不可上移");
      }
    },
     // 下移
     moveDown(index, row) {
      if (index + 1 === this.tableData.length) {
        alert("已经是最后一条，不可下移");
      } else {
        const downDate = this.tableData[index + 1];
        this.tableData.splice(index + 1, 1);
        this.tableData.splice(index, 0, downDate);
      }
    },