在使用ag-grid-react包装器时，每个组件必须有唯一的ID，否则会出现无法创建多个实例的问题。同时，在访问grid API时，需要通过ref引用进行访问。

以下是一个对Aggrid react包装器进行多实例和访问grid API的示例代码：

import React, { Component } from 'react';
import { AgGridReact } from 'ag-grid-react';

class GridComponent extends Component {
  constructor(props) {
    super(props);

    this.state = {
      columnDefs: [...],
      rowData: [...],
    };

    this.gridId = `grid-${Math.floor(Math.random() * 1000)}`;
    this.gridApi = null;
    this.gridColumnApi = null;
    this.gridRef = React.createRef();
  }

  onGridReady(params) {
    this.gridApi = params.api;
    this.gridColumnApi = params.columnApi;

    this.gridApi.setRowData(this.state.rowData);
  }

  onButtonClick() {
    const selection = this.gridApi.getSelectedNodes();
    const selectedData = selection.map(node => node.data);
    console.log(selectedData);
  }

  render() {
    return (
      

        

          
        
        Get selected rows
      
    );
  }
}

export default GridComponent;