关于使用v-pie饼图使用v-for循环给：data数据饼图不显示问题

<el-row :gutter="10">
	<el-col :span="12" v-for="(item, index) in charList" :key="index">
	  <el-card
	    class="el-card-bgcolor"
	    shadow="hover"
	    style="margin-top: 10px"
	  >
	    <h3 slot="header">
		<span>{{ item }}</span>
	    </h3>
	    <ve-pie :data="item" :extend="chartExtend" :key="rowsKey2" />
	  </el-card>
	</el-col>
  </el-row>

getPei(row) {
	let rows = row.name;
	for (let item in rows) {
	  let params = {
	    query: row[rows[item].query],
	    index: "noah_user_*",
	  };
let pieData = {};
	  // let pielist = [];
	  httpPost("", params).then((res) => {
	    console.log("ddd", res);

	    var item = res.data.data[0];
	    var items = [];
	    for (var key in item) {
		var json = {};
		json["name"] = key;
		json["value"] = item[key];
		items.push(json);
	    }
	    //   this.chartData1.rows = items;
	    pieData["columns"] = ["name", "value"];
	    pieData["rows"] = items;
	    //   pielist.push(pieData);
	  });
	  this.rowsKey2 = Math.random();
	  this.charList.push(pieData);
	  this.$forceUpdate();
	  console.log("piepie", this.charList);
	  console.log("rowsKey2", this.rowsKey2);
	}
    },

在第一个标签上增加代码 v-if='charList.length'