ASP.NET MVC Razor中@helper方法的递归调用,在执行过程中会跳过@helper方法内部的代码
本文关键字:方法 @helper 过程中 执行 代码 内部 调用 MVC NET Razor ASP | 更新日期: 2023-09-27 18:27:10
我正在尝试使用@functions&ASP.NET MVC Razor中的助手功能。
我使用@functions成功地创建了嵌套列表,但当我尝试使用@helper方法创建嵌套列表时,执行不会进入helper方法内部。
型号:
public class NavigationMenuModels
{
public int ID { get; set; }
public int? ParentID { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public List<NavigationMenuModels> SubNavigationMenu { get; set; }
}
视图模型:
public class NavigationMenuViewModel
{
public NavigationMenuViewModel()
{
ListMenu = new List<NavigationMenuModels>();
}
public string ListName { get; set; }
public List<NavigationMenuModels> ListMenu { get; set; }
}
控制器:
public ActionResult NavigationMenu()
{
//Menu
NavigationMenuModels objMenu = new NavigationMenuModels() { ID = 1, ParentID = null, Name = "Menu", Description = "Menu" };
//Menu Items
List<NavigationMenuModels> objMenuItems = new List<NavigationMenuModels>();
objMenuItems.Add(new NavigationMenuModels() { ID = 1, ParentID = 1, Name = "Home", Description = "Home" });
objMenuItems.Add(new NavigationMenuModels() { ID = 2, ParentID = 1, Name = "About", Description = "About" });
objMenuItems.Add(new NavigationMenuModels() { ID = 3, ParentID = 1, Name = "Help", Description = "Help" });
objMenuItems.Add(new NavigationMenuModels() { ID = 4, ParentID = 1, Name = "Contact", Description = "Contact" });
objMenu.SubNavigationMenu = objMenuItems;
//Admin
NavigationMenuModels objAdmin = new NavigationMenuModels() { ID = 2, ParentID = null, Name = "Admin", Description = "Admin" };
//Admin Items
List<NavigationMenuModels> objAdminItems = new List<NavigationMenuModels>();
objAdminItems.Add(new NavigationMenuModels() { ID = 1, ParentID=2, Name = "User Permissions", Description = "User Permissions" });
objAdminItems.Add(new NavigationMenuModels() { ID = 2, ParentID=2, Name = "Security", Description = "Security" });
objAdmin.SubNavigationMenu = objAdminItems;
//Account
NavigationMenuModels objAccount = new NavigationMenuModels() { ID = 3, ParentID = null, Name = "Account", Description = "Account" };
//Account Items
List<NavigationMenuModels> objAccountItems = new List<NavigationMenuModels>();
objAccountItems = null;
objAccount.SubNavigationMenu = objAccountItems;
NavigationMenuViewModel objNavigationMenu = new NavigationMenuViewModel();
objNavigationMenu.ListName = "Master Navigation";
objNavigationMenu.ListMenu.Add(objMenu);
objNavigationMenu.ListMenu.Add(objAdmin);
objNavigationMenu.ListMenu.Add(objAccount);
return View(objNavigationMenu);
}
CSHTML:
@using LearnAngularJs_App1.Models
@using System.Text
@model LearnAngularJs_App1.Models.NavigationMenuViewModel
@{
ViewBag.Title = "NavigationMenu";
}
@functions
{
public static HtmlString GetNestedListHtml(NavigationMenuViewModel Crudeinput)
{
StringBuilder sb = new StringBuilder();
var orderedList = new TagBuilder("ol");
foreach (NavigationMenuModels NavMenu in Crudeinput.ListMenu)
{
var listItem = new TagBuilder("li");
listItem.SetInnerText(NavMenu.Name);
sb.AppendLine(listItem.ToString(TagRenderMode.Normal));
if (NavMenu.SubNavigationMenu != null)
{
if (NavMenu.SubNavigationMenu.Count > 0)
{
sb.AppendLine(BuildNestedList(NavMenu.SubNavigationMenu));
}
}
}
orderedList.InnerHtml = sb.ToString();
return new HtmlString(orderedList.ToString(TagRenderMode.Normal));
}
public static string BuildNestedList(List<NavigationMenuModels> SubMenuList)
{
var sb = new StringBuilder();
var orderedList = new TagBuilder("ol");
if (SubMenuList.Count > 0)
{
foreach (NavigationMenuModels SubNavgationMenuitem in SubMenuList)
{
var listItem = new TagBuilder("li");
listItem.SetInnerText(SubNavgationMenuitem.Name);
sb.AppendLine(listItem.ToString(TagRenderMode.Normal));
if (SubNavgationMenuitem.SubNavigationMenu != null)
{
if (SubNavgationMenuitem.SubNavigationMenu.Count > 0)
{
sb.AppendLine(BuildNestedList(SubNavgationMenuitem.SubNavigationMenu));
}
}
}
}
orderedList.InnerHtml = sb.ToString();
return orderedList.ToString(TagRenderMode.Normal);
}
}
@helper BuildNestedListHelper(List<NavigationMenuModels> Crudeinput)
{
if (Crudeinput.Any())
{
<ol>
@foreach (NavigationMenuModels NavMenu in Crudeinput)
{
<li>
@NavMenu.Name
@if (NavMenu.SubNavigationMenu != null)
{
BuildNestedListHelper(NavMenu.SubNavigationMenu);
}
</li>
}
</ol>
}
}
<h2>NavigationMenu</h2>
<div>
<div><span>Bind Navigation Menu using razor @@funtions</span></div>
<div>
@GetNestedListHtml(Model)
</div>
</div>
<div>
<div><span>Bind Navigation Menu using razor @@helper</span></div>
<div>
@BuildNestedListHelper(Model.ListMenu)
</div>
</div>
当对helper方法进行递归调用时,将执行该方法,但跳过执行。
递归调用时只需在方法前面添加"@"即可。