ExtJS4.1+MVC3+Spring.NET1.3+EF5 整合十：TreePanel 之 管理菜单

很遗憾，过去将近一年的时间里一直在学习，工作之中涉及到Java和Flex，业余时间在和朋友搞Android，实际开发中遇到很多问题都需要学习，偶而挤出来那么一点时间自己也在了解一些新的东西，感觉太多的东西想学，只是时间少的可怜。

下一系列准备写个SSH2.0+EasyUI的框架，我还是依旧那么的喜欢开源技术。

Tree结构应该说是Web开发中必会的对象之一，在关系型数据库中体现为一种“一对多”的父子表，最为典型的就是系统“管理菜单”和角色“权限”，在本篇之中，“菜单”和“权限”实际上是一张数据表，“菜单”仅涉及到显示数据，“权限”涉及到更多的ExtJS API操作，正面分别讲解这两种情况下的使用。

1 ExtJS 代码

理论上说“管理菜单”应该根据当前登录用户（所属角色）的权限，显示相应的菜单结构，这个可以通过继承System.Web.Mvc.AuthorizeAttribute来实现，在需要验证权限的Controller或方法上添加“特性(Attribute)”即可。权限的实现过程准备单独写一篇说明。

本文章的“管理菜单”涉及到以下几个js文件：

app/controller/menu.js
app/store/menu.js
app/view/menu/tree.js

1.1 先看一下控制器类（app/controller/menu.js）代码

Ext.define('Manage.controller.Menu', {    extend: 'Ext.app.Controller',    stores: ['Menu'],    views: ['menu.Tree'],    init: function() {this.control({    'menuTree': {            itemclick: this.selectItem        }    });    },    selectItem: function (view, record, item, index) {        Ext.Ajax.request({            url: '/Manage/Category/Query.aspx?id=' + record.data.id,            success: function (response) {                var menu = Ext.JSON.decode(response.responseText);                var url = menu.children.MenuUrl;                if (url.length > 0) {                    var body = Ext.getCmp('bodyID');                    body.removeAll();                    body.add({                        xtype: url                    });                }            }        });    }});

该控制器类很简单，仅仅是涉及到了store和view，这里selectItem方法的作用是选择节点的事件，即向id为bodyID的元素中添加一个新的子元素，其实就是点击左侧菜单时，在右侧打开相应的菜单模块。

1.2 看下store(app/store/menu.js)中的定义

Ext.define('Manage.store.Menu', {extend: 'Ext.data.TreeStore',autoLoad: true,sorters: [{    property: 'leaf',    direction: 'ASC'}],root: {    nodeType: 'async',    expanded: true},    proxy: {        type: 'ajax',        api: {            read: '/Manage/Authorize/Menu.aspx'},reader: {            type: 'json',            root: 'children'        }    }});

“管理菜单”仅涉及到“读”操作，所以这里的proxy只设置了一个read URL：/Manage/Authorize/Menu.aspx，先把view代码看完再回过头看这个URL返回的值。

1.3 view(app/view/menu/tree.js)代码

Ext.define('Manage.view.menu.Tree', {    extend: 'Ext.tree.Panel',    alias: 'widget.menuTree',    header : false,    border : 0,    store: 'Menu',    rootVisible: false});

视图代码很简单，定义了不显示header，边框为0，以及不显示根节点。

2 C# 代码

ExtJS 中相应的controll、store、view代码都很简单，而C#返回的结果也很简单，“管理菜单”所请求的URL是：/Manage/Authorize/Menu.aspx，打开Areas/Manage/Controllers/AuthorizeController.cs文件：

public class AuthorizeController : Controller{    public IRoleService RoleService { get; set; }    public IAuthorizeService AuthorizeService { get; set; }    public ActionResult Menu()    {        Role role = this.RoleService.Read("12");        var childs = this.MenuChildrens(ref role, null);        var root = new        {            id = 0,            text = "根",            expanded = true,            leaf = !childs.Any(),            children = childs        };        return Json(root, JsonRequestBehavior.AllowGet);    }    [NonAction]    private IList<object> MenuChildrens(ref Role role, string parent)    {        var list = String.IsNullOrEmpty(parent)                    ? role.Categories.Where(x => String.IsNullOrEmpty(x.ParentCode))                    : role.Categories.Where(x => x.ParentCode == parent);        IList<object> childs = new List<object>();        if (!list.Any())        {            return childs;        }        foreach (var row in list)        {            var children = this.MenuChildrens(ref role, row.Code);            childs.Add(new            {                id = row.Code,                text = row.Name,                expanded = true,                leaf = !children.Any(),                children = children            });        }        return childs;    }}

在关系型数据库中为了表示一个tree结构，一般都会设计两个主要的字段：ID和父ID，在遍历tree时就可以使用父ID来向下索引子节点。这里的代码我就不详述了，如果有不清晰或疑问请留言。最后，这里实际的返回串类似这样：

{"id":0,"text":"根","expanded":true,"leaf":false,"children":[{"id":"11","text":"数据管理","expanded":true,"leaf":false,"children":[{"id":"1111","text":"新闻管理","expanded":true,"leaf":true,"children":[]}]},{"id":"12","text":"系统管理","expanded":true,"leaf":false,"children":[{"id":"1211","text":"文章模版","expanded":true,"leaf":true,"children":[]}]},{"id":"13","text":"系统配置","expanded":true,"leaf":false,"children":[{"id":"1311","text":"角色管理","expanded":true,"leaf":true,"children":[]},{"id":"1312","text":"管理员管理","expanded":true,"leaf":true,"children":[]},{"id":"1313","text":"权限分配","expanded":true,"leaf":true,"children":[]},{"id":"1314","text":"分类管理","expanded":true,"leaf":true,"children":[]},{"id":"1315","text":"文章管理","expanded":true,"leaf":true,"children":[]}]}]}

使用工具格式化一下再看就比较清晰了：

在线格式化工具：http://tool.oschina.net/codeformat/json

或者使用Sublime Text编辑器，64位：http://download.csdn.net/detail/xz2001/6490993，32位：http://download.csdn.net/detail/xz2001/6490973

{"id": 0,"text": "根","expanded": true,"leaf": false,"children": [{"id": "11","text": "数据管理","expanded": true,"leaf": false,"children": [{"id": "1111","text": "新闻管理","expanded": true,"leaf": true,"children": []}]}, {"id": "12","text": "系统管理","expanded": true,"leaf": false,"children": [{"id": "1211","text": "文章模版","expanded": true,"leaf": true,"children": []}]}, {"id": "13","text": "系统配置","expanded": true,"leaf": false,"children": [{"id": "1311","text": "角色管理","expanded": true,"leaf": true,"children": []}, {"id": "1312","text": "管理员管理","expanded": true,"leaf": true,"children": []}, {"id": "1313","text": "权限分配","expanded": true,"leaf": true,"children": []}, {"id": "1314","text": "分类管理","expanded": true,"leaf": true,"children": []}, {"id": "1315","text": "文章管理","expanded": true,"leaf": true,"children": []}]}]}

返回的节点属性中，id必须唯一，text是显示出的文本，expanded表示默认该节点是否打开，leaf表示是否是叶节点，children是子节点集合，详细的属性请查阅ExtJS API文档，最终显示的结果如下：

下一篇说下TreePanel一些复杂的操作，如节点遍历和复选框的读、写操作等。