DynamicNodeProviderBase +分页

Question

我有ASP.NET MVC项目，我有一些模块。有些模块具有分页功能。对于测试和了解MvcSiteMapProvider我有一个模块论坛工作，并创建ForumDynamicNodeProvider类

public class ForumDynamicNodeProvider : DynamicNodeProviderBase 
{ 
    private readonly IForumsService _forumsService; 

    public ForumDynamicNodeProvider(IForumsService forumsService) 
    { 
     this._forumsService = forumsService; 
    } 

    public override IEnumerable<DynamicNode> GetDynamicNodeCollection(ISiteMapNode node) 
    { 
     string rootTitle = ManagerLocalization.Get("Forums", "FORUMS"); 


     var nodes = new List<DynamicNode> 
         { 
          new DynamicNode 
           { 
            Title = rootTitle, 
            Controller = "Forums", 
            Action = "Index", 
            Key = "forum_home" 
           } 
         }; 

     var forums = this._forumsService.GetForums<ForumNode>().ToList(); 
     var topics = this._forumsService.GetTopics<TopicNode>().ToList(); 

     foreach (var forum in forums) 
     { 
      var parentForum = this.GetParentForum(forums, forum); 
      string parentKey = parentForum?.Id.ToString() ?? "home"; 

      var forumRouteValue = new Dictionary<string, object> { { "forumName", forum.NameTranslit } }; 

      nodes.Add(new DynamicNode 
      { 
       Key = $"forum_{forum.Id}", 
       ParentKey = $"forum_{parentKey}", 
       Title = forum.Name, 
       Controller = "Forums", 
       Action = "ShowForum", 
       RouteValues = forumRouteValue 
      }); 
     } 

     foreach (var topic in topics) 
     { 
      var forum = forums.FirstOrDefault(item => item.Id == topic.ForumId); 
      var forumRouteValue = new Dictionary<string, object> { { "forum", forum.NameTranslit }, { "topicName", topic.TitleTranslite }, {"page", 0 } }; 

      nodes.Add(new DynamicNode 
      { 
       Key = $"topic_{topic.Id}", 
       ParentKey = $"forum_{topic.ForumId}", 
       Title = topic.Title, 
       Controller = "Forums", 
       Action = "ShowTopic", 
       RouteValues = forumRouteValue 
      }); 
     } 

     return nodes; 
    } 

    private ForumNode GetParentForum(List<ForumNode> forums, ForumNode forum) 
    { 
     if (forum.ForumId > 0) 
     { 
      return forums.FirstOrDefault(item => item.Id == forum.ForumId); 
     } 

     return null; 
    } 
} 

但我不能找到分页一个很好的决定。为了方便起见，我可以使用页面前缀键和重复的DynamicNode。但这是个坏主意，因为当我有1000个主题的例子，每个主题有20个页面时，我必须创建20000个DynamicNode。也许有其他决定？

Answer 1

对于环境上下文（例如页码），您可以使用PreservedRouteParameters至force a match作为指定键的任何值。这些键与请求中的路由值或查询字符串参数相匹配（如果它们相同，则路由值优先）。

foreach (var forum in forums) 
{ 
    var parentForum = this.GetParentForum(forums, forum); 
    string parentKey = parentForum?.Id.ToString() ?? "home"; 

    var forumRouteValue = new Dictionary<string, object> { { "forumName", forum.NameTranslit } }; 

    // Always match the "page" route value regardless of its value 
    var forumPreservedRouteParameters = new List<string>() { "page" }; 

    nodes.Add(new DynamicNode 
    { 
     Key = $"forum_{forum.Id}", 
     ParentKey = $"forum_{parentKey}", 
     Title = forum.Name, 
     Controller = "Forums", 
     Action = "ShowForum", 
     RouteValues = forumRouteValue, 
     PreservedRouteParameters = forumPreservedRouteParameters 
    }); 
} 

注：当您使用PreservedRouteParameters，它们包含在当前请求生成的URL，如果提供，如果不是在请求中提供不包含在URL中。因此，如果同一祖先中有多个页码，则需要为每个页面分配一个单独的路由键名称，否则当前页码将从当前请求传递给祖先节点。