el-table修改一行数据后让表格更新

<el-table border ref="multipleTable" :data="tableData" style="width: 100%">
    <el-table-column prop="tuzai" width="80" label="屠宰数量" align="center"></el-table-column>
    <el-table-column label="操作" align="center" width="100">
					<template slot-scope="scope">
						<el-button type="text" @click="modifynum(scope.row, scope.$index)">修改屠宰数量</el-button>
					</template>
     </el-table-column>
 </el-table>

modifynum(val, indexs) {
    val.tuzai = '1111';
    // console.log('修改为',value,'行',indexs);
    this.tableData[indexs].tuzai = JSON.parse(value);
    val.tuzai = JSON.parse(value);
    this.$set(this.tableData, indexs, val);
}