ExtJS动态创建树结构
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????? 这两天在研究ExtJS，对其有了深刻的认识。总结如下：
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?????????? ?根据显示数据量，决定Ext树的类型。如果是大数据量，一般采用创建Ext.tree.AsyncTreeNode根节点的方式
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(即每点击一个树节点后，动态的从后台读取数据。优点：加快显示速度) 。如果数据量小，一般采用Ext.tree.TreeNode
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这样的根节点。
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????? 第一种代码如下：
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<%@ page language="java" contentType="text/html; charset=GBK" pageEncoding="GBK"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=GBK"><link rel="stylesheet" type="text/css" href="../extjs/resources/css/ext-all.css"/><script type="text/javascript" src="../extjs/adapter/ext/ext-base.js"></script><script type="text/javascript" src="../extjs/ext-all.js"></script><title>树结构</title><script type="text/javascript">Ext.onReady(function() {var root = new Ext.tree.AsyncTreeNode({id : "root",text : "树的根"});var loader = new Ext.tree.TreeLoader({url : '<%=request.getContextPath()%>/User_getNodeTree'});loader.on("beforeload", function(loader, node) { alert("---"+node.id);loader.baseParams.nodeId = node.id;});var tree = new Ext.tree.TreePanel({renderTo : "tree",root : root,loader : loader,width : 200,height : 300});});</script></head><body> <!-- 要有一定高度Ext2.0,不然看不见 --><div id="tree" style="overflow:auto; height:100%;width:250px;border:5px solid #c3daf9;"></div> </body></html>?
??? 实体描述：构造包括 id,text,cls,leaf,href属性的实体
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????后台返回数据：
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?????????? 每次点击一个树节点后，从后台读取该节点的子节点的信息。例如：
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????????????? [{text:'用户',href:'test.jsp',leaf:true},
????????????? ?{text:'管理员',href:'##',leaf:true}]
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第二种树：
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???页面：
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<%@ page language="java" contentType="text/html; charset=GBK" pageEncoding="GBK"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=GBK"><link rel="stylesheet" type="text/css" href="../extjs/resources/css/ext-all.css"/><script type="text/javascript" src="../extjs/adapter/ext/ext-base.js"></script><script type="text/javascript" src="../extjs/ext-all.js"></script><title>树结构</title><script type="text/javascript">Ext.onReady(function() {var treePanel=new Ext.tree.TreePanel({ renderTo : "tree", useArrows:true, autoScroll:true, animate:true, enableDD:true, //是否显示跟节点 rootVisible:false, frame: true, containerScroll: true }); var root=new Ext.tree.AsyncTreeNode({ id:'4', text:'root', leaf:false, loader:new Ext.tree.TreeLoader({dataUrl:'/User_getNodeTree'})}); treePanel.setRootNode(root); treePanel.getRootNode().expand(true);});</script></head><body> <!-- 要有一定高度Ext2.0,不然看不见 --><div id="tree" style="overflow:auto; height:100%;width:250px;border:5px solid #c3daf9;"></div> </body></html>????????
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??? 实体类：
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package com.order.entity;import java.util.List;public class TreeModule{/** 此bean用于构建树向其中注入有关的信息，将SysModule中的信息拷贝到JsonTreeModule中*/private String id; //ID private String text; //节点显示 private String cls; //图标 private boolean leaf; //是否叶子 private String href; //链接 private String hrefTarget; //链接指向 private boolean expandable; //是否展开 private String description; //描述信息 private List<TreeModule> children;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getText() {return text;}public void setText(String text) {this.text = text;}public String getCls() {return cls;}public void setCls(String cls) {this.cls = cls;}public boolean isLeaf() {return leaf;}public void setLeaf(boolean leaf) {this.leaf = leaf;}public String getHref() {return href;}public void setHref(String href) {this.href = href;}public String getHrefTarget() {return hrefTarget;}public void setHrefTarget(String hrefTarget) {this.hrefTarget = hrefTarget;}public boolean isExpandable() {return expandable;}public void setExpandable(boolean expandable) {this.expandable = expandable;}public String getDescription() {return description;}public void setDescription(String description) {this.description = description;}public List<TreeModule> getChildren() {return children;}public void setChildren(List<TreeModule> children) {this.children = children;}}?
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??? Struts2：
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/** * 创建菜单树结构 * @return */public String getNodeTree(){PrintWriter out=null;response.setContentType("text/html;charset=GBK");try {out=response.getWriter();} catch (IOException e) {e.printStackTrace();}User user=(User)session.getAttribute("user");if(user!=null){UserService uservice=new UserService();String allprivs=user.getPrivs();List<String> privsList=Arrays.asList(allprivs.trim().split(","));List<MenuPanel> menulist=uservice.getAllNodes();List<TreeModule> list=new ArrayList<TreeModule>();for(MenuPanel mp:menulist){if(mp.getParantNodeID()==0){TreeModule treeNode=new TreeModule();treeNode.setId(mp.getNodeId());treeNode.setText(mp.getMenuName());treeNode.setLeaf(mp.isLeaf());treeNode.setHref(mp.getActionPath());List<TreeModule> children=new ArrayList<TreeModule>();for(MenuPanel menu:menulist){ if(menu.getParantNodeID().intValue()==mp.getId().intValue() &&privsList.contains(menu.getNodeId().trim())){ TreeModule subtreeNode=new TreeModule(); subtreeNode.setId(menu.getNodeId()); subtreeNode.setText(menu.getMenuName()); subtreeNode.setLeaf(menu.isLeaf()); subtreeNode.setHref(menu.getActionPath()); children.add(subtreeNode); }}if(children.size()>0){treeNode.setChildren(children);list.add(treeNode);}}}JSONArray obj=JSONArray.fromObject(list);String res = obj.toString();out.println(res);}return null;}?
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????? 有些地方参考网上的一些代码。
1 楼 minisnakecjh 2012-03-30 代码没有贴完整