ElementUI实现表格（table） 行上下移动的效果

<div id="app">
    <el-table :data="URLModles" :show-header="false" highlight-current-row style="width: 100%"
      @selection-change="handleSelectionChange">
      <el-table-column type="selection" width="55px">
      </el-table-column>
      <el-table-column type="index" width="55px">
      </el-table-column>
      <el-table-column prop="expressCode" label="快递代码" width="100px">
      </el-table-column>
      <el-table-column prop="expressName" label="快递名称" width="100px">
      </el-table-column>
      <el-table-column label="操作">
        <template slot-scope="scope">
          <el-button size="mini" :disabled="scope.$index===0" @click="moveUp(scope.$index,scope.row)"><i
              class="el-icon-arrow-up"></i></el-button>
          <el-button size="mini" :disabled="scope.$index===(URLModles.length-1)"
            @click="moveDown(scope.$index,scope.row)"><i class="el-icon-arrow-down"></i></el-button>
          <el-button type="info" size="mini" round v-if="scope.$index===0">默认</el-button>
        </template>
      </el-table-column>
    </el-table>
  </div>

var vm = new Vue({
    el: "#app",
    data() {
      return {
        URLModles: [{
          index: '1',
          expressCode: 'SF',
          expressName: '顺丰快递',
          status: true,
        }, {
          index: '2',
          expressCode: 'YTO',
          expressName: '圆通快递',
          status: true,
        }, {
          index: '3',
          expressCode: 'UC',
          expressName: '优速快递',
          status: true,
        }],
        multipleSelection: []
      }
    },
    methods: {
      //选择复选框数据
      handleSelectionChange(val) {
        this.multipleSelection = val;
      },
      //上移
      moveUp(index, row) {
        var that = this;
        console.log('上移', index, row);
        console.log(that.URLModles[index]);
        if (index > 0) {
          let upDate = that.URLModles[index - 1];
          that.URLModles.splice(index - 1, 1);
          that.URLModles.splice(index, 0, upDate);
        } else {
          alert('已经是第一条，不可上移');
        }
      },
      //下移
      moveDown(index, row) {
        var that = this;
        console.log('下移', index, row);
        if ((index + 1) === that.URLModles.length) {
          alert('已经是最后一条，不可下移');
        } else {
          console.log(index);
          // 保存下一条数据
          let downDate = that.URLModles[index + 1];
          // 删除下一条数据
          that.URLModles.splice(index + 1, 1);
          // 增添被删除的那一条数据
          that.URLModles.splice(index, 0, downDate);
        }
      }
    }
  })
</script>