使用MvcSiteMap如何创建到下一个和前一个节点的链接？

Question

我想实现在MvcSiteMapProvider类似如下的HTML助手：

Html.MvcSiteMap().Previous() 
Html.MvcSiteMap().Next() 

不过，我很新的他们的API，是有可能做到这一点，如果是的话，怎么样？

Answer 1

您可以通过构建自定义HTML助手来完成此操作。我已经在GitHub上提供answered this question并提供working demo project，但我在这里复制以供参考。

上下文档的逻辑看起来像这样，剩下的代码大部分是样板模板HTML辅助代码。

private static ISiteMapNode GetNextNode(ISiteMapNode startingNode, IDictionary<string, object> sourceMetadata) 
{ 
    ISiteMapNode nextNode = null; 
    if (startingNode.HasChildNodes) 
    { 
     // Get the first child node 
     nextNode = startingNode.ChildNodes[0]; 
    } 
    else if (startingNode.ParentNode != null) 
    { 
     // Get the next sibling node 
     nextNode = startingNode.NextSibling; 
     if (nextNode == null) 
     { 
      // If there are no more siblings, the next position 
      // should be the parent's next sibling 
      var parent = startingNode.ParentNode; 
      if (parent != null) 
      { 
       nextNode = parent.NextSibling; 
      } 
     } 
    } 

    // If the node is not visible or accessible, run the operation recursively until a visible node is found 
    if (nextNode != null && !(nextNode.IsVisible(sourceMetadata) || nextNode.IsAccessibleToUser())) 
    { 
     nextNode = GetNextNode(nextNode, sourceMetadata); 
    } 

    return nextNode; 
} 

private static ISiteMapNode GetPreviousNode(ISiteMapNode startingNode, IDictionary<string, object> sourceMetadata) 
{ 
    ISiteMapNode previousNode = null; 

    // Get the previous sibling 
    var previousSibling = startingNode.PreviousSibling; 
    if (previousSibling != null) 
    { 
     // If there are any children, go to the last descendant 
     if (previousSibling.HasChildNodes) 
     { 
      previousNode = previousSibling.Descendants.Last(); 
     } 
     else 
     { 
      // If there are no children, return the sibling. 
      previousNode = previousSibling; 
     } 
    } 
    else 
    { 
     // If there are no more siblings before this one, go to the parent node 
     previousNode = startingNode.ParentNode; 
    } 

    // If the node is not visible or accessible, run the operation recursively until a visible node is found 
    if (previousNode != null && !(previousNode.IsVisible(sourceMetadata) || previousNode.IsAccessibleToUser())) 
    { 
     previousNode = GetPreviousNode(previousNode, sourceMetadata); 
    } 

    return previousNode; 
}