解析jquery easyui tree异步加载子节点问题

easyui中的树可以从标记中建立，也可以通过指定一个URL属性读取数据建立。如果想建立一棵异步树，需要为每个节点指定一个id属性值，这样在加载数据时会自动向后台传递id参数。

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编写前台代码：

$('#tt').tree({ url:'/demo2/node/getNodes' // The url will be mapped to NodeController class and getNodes method });

为测试用，建立一个节点的数据模型：

@Table(name="nodes") public class Node extends ActiveRecordBase{ @Id public Integer id; @Column public Integer parentId; @Column public String name; public boolean hasChildren() throws Exception{ long count = count(Node.class, "parentId=?", new Object[]{id}); return count > 0; } }

编写后台的控制器代码：

public class NodeController extends ApplicationController{ /** * get nodes, if the 'id' parameter equals 0 then load the first level nodes, * otherwise load the children nodes * @param id the parent node id value * @return the tree required node json format * @throws Exception */ public View getNodes(int id) throws Exception{ List<Node> nodes = null; if (id == 0){ // return the first level nodes nodes = Node.findAll(Node.class, "parentId=0 or parentId is null", null); } else { // return the children nodes nodes = Node.findAll(Node.class, "parentId=?", new Object[]{id}); } List<Map<String,Object>> items = new ArrayList<Map<String,Object>>(); for(Node node: nodes){ Map<String,Object> item = new HashMap<String,Object>(); item.put("id", node.id); item.put("text", node.name); // the node has children, // set the state to 'closed' so the node can asynchronous load children nodes if (node.hasChildren()){ item.put("state", "closed"); } items.add(item); } return new JsonView(items); } }

官网例子地址：

demo下载：easyui-tree2_jb51.rar 

重要的事情说三遍!!!

$('#tt').tree({ 　　method:"POST", url:'/demo2/node/getNodes' // The url will be mapped to NodeController class and getNodes method });