customsitemapprovider.cs

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using System;
using System.Configuration.Provider;
using System.Collections;
using System.Collections.Specialized;
using System.IO;
using System.Security.Permissions;
using System.Web;

namespace SiteMapDemo
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public class CustomSiteMapProvider : SiteMapProvider
    {

        private SiteMapProvider parentSiteMapProvider = null;
        private string simpleTextProviderName = null;
        private string sourceFilename = null;
        private SiteMapNode rootNode = null;
        private ArrayList siteMapNodes = null;
        private ArrayList childParentRelationship = null;

        public CustomSiteMapProvider()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }

        // Implement the CurrentNode property.
        public override SiteMapNode CurrentNode
        {
            get
            {
                string currentUrl = FindCurrentUrl();
                // Find the SiteMapNode that represents the current page.
                SiteMapNode currentNode = FindSiteMapNode(currentUrl);
                return currentNode;
            }
        }

        // Implement the RootNode property.
        public override SiteMapNode RootNode
        {
            get
            {
                return rootNode;
            }
        }
        // Implement the ParentProvider property.
        public override SiteMapProvider ParentProvider
        {
            get
            {
                return parentSiteMapProvider;
            }
            set
            {
                parentSiteMapProvider = value;
            }
        }

        // Implement the RootProvider property.
        public override SiteMapProvider RootProvider
        {
            get
            {
                // If the current instance belongs to a provider hierarchy, it
                // cannot be the RootProvider. Rely on the ParentProvider.
                if (this.ParentProvider != null)
                {
                    return ParentProvider.RootProvider;
                }
                // If the current instance does not have a ParentProvider, it is
                // not a child in a hierarchy, and can be the RootProvider.
                else
                {
                    return this;
                }
            }
        }
        // Implement the FindSiteMapNode method.
        public override SiteMapNode FindSiteMapNode(string rawUrl)
        {

            // Does the root node match the URL?
            if (RootNode.Url == rawUrl)
            {
                return RootNode;
            }
            else
            {
                SiteMapNode candidate = null;
                // Retrieve the SiteMapNode that matches the URL.
                lock (this)
                {
                    candidate = GetNode(siteMapNodes, rawUrl);
                }
                return candidate;
            }
        }
        // Implement the GetChildNodes method.
        public override SiteMapNodeCollection GetChildNodes(SiteMapNode node)
        {
            SiteMapNodeCollection children = new SiteMapNodeCollection();
            // Iterate through the ArrayList and find all nodes that have the specified node as a parent.
            lock (this)
            {
                for (int i = 0; i < childParentRelationship.Count; i++)
                {

                    string nodeUrl = ((DictionaryEntry)childParentRelationship[i]).Key as string;

                    SiteMapNode parent = GetNode(childParentRelationship, nodeUrl);

                    if (parent != null && node.Url == parent.Url)
                    {
                        // The SiteMapNode with the Url that corresponds to nodeUrl
                        // is a child of the specified node. Get the SiteMapNode for
                        // the nodeUrl.
                        SiteMapNode child = FindSiteMapNode(nodeUrl);
                        if (child != null)
                        {
                            children.Add(child as SiteMapNode);
                        }
                        else
                        {
                            throw new Exception("ArrayLists not in sync.");
                        }
                    }
                }
            }
            return children;
        }
        protected override SiteMapNode GetRootNodeCore()
        {
            return RootNode;
        }
        // Implement the GetParentNode method.
        public override SiteMapNode GetParentNode(SiteMapNode node)
        {
            // Check the childParentRelationship table and find the parent of the current node.
            // If there is no parent, the current node is the RootNode.
            SiteMapNode parent = null;
            lock (this)
            {
                // Get the Value of the node in childParentRelationship
                parent = GetNode(childParentRelationship, node.Url);
            }
            return parent;
        }

        // Implement the ProviderBase.Initialize property.
        // Initialize is used to initialize the state that the Provider holds, but
        // not actually build the site map.
        public override void Initialize(string name, NameValueCollection attributes)
        {

            lock (this)
            {

                base.Initialize(name, attributes);

                simpleTextProviderName = name;
                sourceFilename = attributes["siteMapFile"];
                siteMapNodes = new ArrayList();
                childParentRelationship = new ArrayList();

                // Build the site map in memory.
                LoadSiteMapFromStore();
            }
        }
        // Private helper methods

        private SiteMapNode GetNode(ArrayList list, string url)
        {
            for (int i = 0; i < list.Count; i++)
            {
                DictionaryEntry item = (DictionaryEntry)list[i];
                if ((string)item.Key == url)
                    return item.Value as SiteMapNode;
            }
            return null;
        }

        // Get the URL of the currently displayed page.
        private string FindCurrentUrl()
        {
            try
            {
                // The current HttpContext.
                HttpContext currentContext = HttpContext.Current;
                if (currentContext != null)
                {
                    return currentContext.Request.RawUrl;
                }
                else
                {
                    throw new Exception("HttpContext.Current is Invalid");
                }
            }
            catch (Exception e)
            {
                throw new NotSupportedException("This provider requires a valid context.", e);
            }
        }
        protected virtual void LoadSiteMapFromStore()
        {
            string pathToOpen;

            lock (this)
            {
                try
                {
                    // If a root node exists, LoadSiteMapFromStore has already
                    // been called, and the method can return.
                    if (rootNode != null)
                    {
                        return;
                    }
                    else
                    {
                        pathToOpen = HttpContext.Current.Server.MapPath("~" + "\\" + sourceFilename);

                        if (File.Exists(pathToOpen))
                        {
                            // Open the file to read from.
                            using (StreamReader sr = File.OpenText(pathToOpen))
                            {

                                // Clear the state of the collections and rootNode
                                rootNode = null;
                                siteMapNodes.Clear();
                                childParentRelationship.Clear();

                                // Parse the file and build the site map
                                string s = "";
                                string[] nodeValues = null;
                                SiteMapNode temp = null;

                                while ((s = sr.ReadLine()) != null)
                                {

                                    // Build the various SiteMapNode objects and add
                                    // them to the ArrayList collections. The format used
                                    // is: URL,TITLE,DESCRIPTION,PARENTURL

                                    nodeValues = s.Split(',');

                                    temp = new SiteMapNode(this,
                                        HttpRuntime.AppDomainAppVirtualPath + "/" + nodeValues[0],
                                        HttpRuntime.AppDomainAppVirtualPath + "/" + nodeValues[0],
                                        nodeValues[1],
                                        nodeValues[2]);

                                    // Is this a root node yet?
                                    if (null == rootNode &&
                                        (null == nodeValues[3] || nodeValues[3] == String.Empty))
                                    {
                                        rootNode = temp;
                                    }

                                    // If not the root node, add the node to the various collections.
                                    else
                                    {
                                        siteMapNodes.Add(new DictionaryEntry(temp.Url, temp));
                                        // The parent node has already been added to the collection.
                                        SiteMapNode parentNode =
                                                 FindSiteMapNode(HttpRuntime.AppDomainAppVirtualPath + "/" + nodeValues[3]);
                                        if (parentNode != null)
                                        {
                                            childParentRelationship.Add(new DictionaryEntry(temp.Url, parentNode));
                                        }
                                        else
                                        {
                                            throw new Exception("Parent node not found for current node.");
                                        }
                                    }
                                }
                            }
                        }
                        else
                        {
                            throw new Exception("File not found");
                        }

                    }
                }
                catch (Exception e)
                {
                    string aa = e.Message;
                }
            }
            return;
        }
    }
}