vue-element-table滚动加载时如何保持勾选

<el-table :row-key="getRowKeys"> 
<el-table-column type="selection" :selectable="selectable" :reserve-selection="true"> </el-table-column>

保持勾选

:row-key="getRowKeys" 
:reserve-selection="true"
getRowKeys(row:any){ 
return row.id // 设定每一条对应一个key 
}