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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>
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??? 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：
????????
????????????? [{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