C#无限极分类树-创建-排序-读取用Asp.NetCore+EF实现

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原作者: [db:作者] 来自: [db:来源] 收藏邀请

今天做一个管理后台菜单，想着要用无限极分类，记得园子里还是什么地方见过这种写法，可今天找了半天也没找到，没办法静下心来自己写了：

首先创建节点类（我给它取名：AdminUserTree）：

 1 /// <summary>
 2     /// 无限极节点类
 3     /// </summary>
 4     public class AdminUserTree
 5     {
 6         /// <summary>
 7         /// 节点信息
 8         /// </summary>
 9         public int NodeID { get; set; }
10         /// <summary>
11         /// 节点名称
12         /// </summary>
13         public string NodeName { get; set; }
14         /// <summary>
15         /// 父节点ID
16         /// </summary>
17         public int ParentID { get; set; }
18         /// <summary>
19         /// 对应的链接地址
20         /// </summary>
21         public string Url { get; set; }
22         public int? PermissionID { get; set; }
23         public int? OrderID { get; set; }
24         public string Location { get; set; }        
25         public string comment { get; set; }           
26         public string ImageUrl { get; set; }
27         /// <summary>
28         /// 层级
29         /// </summary>
30         public int level { get; set; }
31         /// <summary>
32         /// 子节点数目（很重要）
33         /// </summary>
34         public int childNumberl { get; set; }
35 
36         /// <summary>
37         ///  子节点 （子节点是一个List）这种用法叫什么?
38         /// </summary>
39         public List<AdminUserTree> childNode { get; set; }
40     }

为无限极分类填充数据，由于考虑到示来管理后台每个页面都会调用到，这里我为控制器创建了一个基类方法

 1 /// <summary>
 2     /// 管理页面基类（MVC Controller）
 3     /// </summary>
 4     public class AdminBase: Controller
 5     {
 6         /// <summary>
 7         /// EF数据访问配置
 8         /// </summary>
 9         private readonly ApplicationDbContext _basecontext;
10 
11         /// <summary>
12         /// 管理菜单 这里是基数，声明为属性以便控制器里面可以用到
13         /// </summary>
14         public AdminUserTree leftMenu { get; set; }
15 
16 
17         public AdminBase(ApplicationDbContext context)
18         {
19             _basecontext = context;
20             //初始化无限极分类管理菜单
21             buildtree();
22         }
23 
24         /// <summary>
25         /// 建立无限极节点树-管理菜单
26         /// </summary>
27         public void buildtree()
28         {
29             AdminUserTree result = new AdminUserTree();
30             //初始化一个节点做为根节点
31             result.NodeID = 0;
32             result.NodeName= "管理员菜单";
33             result.Url = "";
34             result.ParentID = -1;
35             result.Location = "";
36             result.OrderID = 0;
37             result.comment = "";
38             result.ImageUrl = "";
39             result.PermissionID = 0;
40             result.level = 0;
41             result.childNumberl = 0;
42             //把根节点传递给递归方法去创建子节点
43             result.childNode=BuildMenuTree(result, -1);
44             leftMenu = result;
45         }
46 
47         /// <summary>
48         /// 递归创建子节点方法
49         /// </summary>
50         /// <param name="node">要为其分配子节点的父级节点</param>
51         /// <param name="levelID">层级关系</param>
52         /// <returns></returns>
53         protected  List<AdminUserTree> BuildMenuTree(AdminUserTree node, int levelID)
54         {
55             var listtree = _basecontext.Admintree;
56 
57             //从数据库中取出node节点的全部子节点 条件：m.ParentID==node.NodeID
58             List<AdminUserTree> lt  =  listtree.Where(m => m.ParentID==node.NodeID )
59                                             .Select(m=>new AdminUserTree() {
60                                             NodeID =m.NodeID
61                                             ,NodeName=m.NodeName
62                                             ,Url=m.Url
63                                             ,ParentID=m.ParentID
64                                             ,Location=m.Location
65                                             ,OrderID=m.OrderID
66                                             ,comment=m.comment
67                                             ,ImageUrl=m.ImageUrl
68                                             ,PermissionID=m.PermissionID})
69                                             .ToList();
70 
71             if (lt != null)
72             {
73                 //节点深度
74                 node.level = levelID + 1;
75                 //子节点数量，便于前端递归输出时调用
76                 node.childNumberl = lt.Count;
77                 for (int i = 0; i < lt.Count; i++)               
78                 {
79                     //递归调用创建子节点
80                     lt[i].childNode = BuildMenuTree(lt[i], node.level);
81                 }
82                 return lt;
83 
84             }
85             else {
86                 return null;
87             }            
88 
89          }
90         
91     }

控制器（Controller)继承及调用代码：

 1   public class AdminTreeController : AdminBase
 2     {
 3         private readonly ApplicationDbContext _context;
 4 
 5         
 6         public AdminTreeController(ApplicationDbContext context):base(context)
 7         {
 8             _context = context;    
 9         }
10 
11         // GET: AdminTree
12         public async Task<IActionResult> Index(int id=1)
13         {
14             var treelist = _context.Admintree;
15             var pageOption = new WeiPagerOption
16             {
17                 CurrentPage = id,
18                 PageSize = 15,
19                 Total = await treelist.CountAsync(),
20                 RouteUrl = "/Admintree/Index",
21                 pageNumStep = 5
22             };
23 
24             //分页参数
25             ViewBag.PagerOption = pageOption;
26 
27             //无限极分类菜单绑定在这里
28             ViewBag.mainMenu = leftMenu;
29 
30             //返回主要数据
31             return View(await treelist.OrderByDescending(b => b.OrderID).Skip((pageOption.CurrentPage - 1) * pageOption.PageSize).Take(pageOption.PageSize).ToListAsync());
32         }
33 ｝

View层代码：

  1 @model IEnumerable<Hxwei.WebWQSF.Models.AdminTreeModel>
  2 @using Hxwei.WebWQSF;
  3 @using Hxwei.WebWQSF.Controllers;
  4 @using System.Text;
  5 @{
  6     ViewData["Title"] = "菜单管理";
  7 }
  8 @functions
  9 {
 10     public string getAdminMenu(AdminUserTree node)
 11     {
 12         StringBuilder sb = new StringBuilder();
 13 
 14         List<AdminUserTree> ls = node.childNode;
 15         if(ls.Count>0)
 16         {
 17             //遍历每个子节点以输出，这里用到了排序ls.OrderBy(m => m.OrderID)
 18             foreach (var r in ls.OrderBy(m => m.OrderID))
 19             {
 20                 if (r.childNumberl > 0)
 21                 {
 22                     //当存在子菜单时的方法，这里会有递归调用
 23                     sb.Append("<div class=\"btn-group\">");
 24                     sb.Append("<button type=\"button\" class=\"btn btn-default dropdown-toggle\" data-toggle=\"dropdown\">");
 25                     sb.Append(r.NodeName);
 26                     sb.Append("<span class=\"caret\"></span>");
 27                     sb.Append("</button>");
 28                     sb.Append("<ul class=\"dropdown-menu\" role=\"menu\">");
 29                     //递归调用
 30                     sb.Append(getAdminMenu(r));
 31                     sb.Append("</ul>");
 32                     sb.Append("</div>");
 33 
 34                 }
 35                 else
 36                 {
 37                     //当不存在子菜单时输出
 38                     string ntext = string.Format("<li><a href=\"{0}\">{1}</a></li>",r.Url,r.NodeName);
 39                     sb.Append(ntext);
 40 
 41                 }
 42             }
 43 
 44         }
 45 
 46 
 47         return sb.ToString();
 48     }
 49 }
 50 <div class="row">
 51     <div class="col-md-3 navbar-inverse">
 52         <div class="btn-group-vertical col-md-10">
 53             
 54             <button type="button" class="btn btn-default">@ViewBag.mainMenu.NodeName</button>
 55             @Html.Raw(getAdminMenu(ViewBag.mainMenu));
 56           
 57         </div>
 58 
 59     </div>
 60     <div class="col-md-9">
 61         <h2>Index</h2>
 62 
 63         <p>
 64             <a asp-action="Create">Create New</a>
 65         </p>
 66         <table class="table">
 67             <thead>
 68                 <tr>
 69                     <th>
 70                         @Html.DisplayNameFor(model => model.NodeName)
 71                     </th>
 72                     <th>
 73                         @Html.DisplayNameFor(model => model.ParentPath)
 74                     </th>
 75                     <th>
 76                         @Html.DisplayNameFor(model => model.OrderID)
 77                     </th>
 78                     <th>
 79                         @Html.DisplayNameFor(model => model.Url)
 80                     </th>
 81                     <th></th>
 82                 </tr>
 83             </thead>
 84             <tbody>
 85                 @foreach (var item in Model)
 86                 {
 87                 <tr>
 88                     <td>
 89                         @Html.DisplayFor(modelItem => item.NodeName)
 90                     </td>
 91                     <td>
 92                         @Html.DisplayFor(modelItem => item.ParentPath)
 93                     </td>
 94                     <td>
 95                         @Html.DisplayFor(modelItem => item.OrderID)
 96                     </td>
 97                     <td>
 98                         @Html.DisplayFor(modelItem => item.Url)
 99                     </td>
100                     <td>
101                         <a asp-action="Edit" asp-route-id="@item.NodeID">Edit</a> |
102                         <a asp-action="Details" asp-route-id="@item.NodeID">Details</a> |
103                         <a asp-action="Delete" asp-route-id="@item.NodeID">Delete</a>
104                     </td>
105                 </tr>
106                 }
107             </tbody>
108             <tr><td colspan="5" align="center"><pager pager-option="ViewBag.PagerOption as WeiPagerOption"></pager></td></tr>
109         </table>
110     </div>
111 </div>