1. 首先，我们需要创建一个相应的工具栏按钮，并为其定义一个函数和事件监听器。以下是示例代码：

function onToolbarButtonClick(){
  var selectedRows = gridOptions.api.getSelectedRows();
  // code to handle selected rows
}

var toolbarButton = document.createElement('button');
toolbarButton.innerHTML = 'Drag and Drop';
toolbarButton.addEventListener('click', onToolbarButtonClick);
var toolbarDiv = document.querySelector('#toolbar');
toolbarDiv.appendChild(toolbarButton);

2. 然后，我们需要为 Ag-grid 添加 dnd 监听器，并处理从工具栏拖放到网格的逻辑。以下是示例代码：

// define drop zone
var dropZoneParams = {
  getContainer: function(){
    return gridOptions.api.getDropTarget();
  },
  onDragEnter: function(e){
    // code to handle drag entering grid
  },
  onDragLeave: function(e){
    // code to handle drag leaving grid
  },
  onDrop: function(e){
    var node = e.dragData.node;
    if(!node){
      return;
    }
    var data = node.data;
    gridOptions.api.updateRowData({add: [data]});
  }
};

// add toolbar button dnd
var toolbarButtonDragListener = {
  onDragStart: function(e){
    var selectedNodes = gridOptions.api.getSelectedNodes();
    if(!selectedNodes || !selectedNodes.length){
      return null;
    }
    var selectedData = selectedNodes.map(function(node){ return node.data; });
    return {
      eventData: selectedData,
      draggedNodes: selectedNodes,
      node: selectedNodes[0]
    };
  },
  onDragEnd: function(e){
    // code to handle dnd ending
  }
};

// add dnd to grid
var gridDragAndDrop = {
  onGridReady: function(params){
    var gridApi = params.api;
    var dropZone = gridOptions.api.getDropTarget();
    gridApi.addCellDropZone(dropZoneParams);
    gridApi.addRowDropZone(dropZoneParams);
  }
};

// initialize grid options
var gridOptions = {
  // your grid options
  onGridReady: gridDragAndDrop.onGridReady,
  getDropTarget: function(){
    return document.querySelector('#grid-wrapper');
  },
  rowDragManaged: true,
  allowContextMenuWithControlKey: true,
  rowSelection: 'multiple',
  columnDefs: [
    {headerName: 'Column 1', field: 'col_1'},
    {headerName: 'Column 2', field: 'col_2'},
    {headerName: 'Column 3', field: