应用AJAX技术，获取SharePoint信息。

using System;
using System.Text;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls.WebParts;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Administration;

namespace SPS2007.Research.WebParts
...{
    public class AjaxPart : WebPart, ICallbackEventHandler
    ...{

        private HtmlButton btnCall;

        protected override void CreateChildControls()
        ...{
            base.CreateChildControls();

            btnCall = new HtmlButton();
            
            btnCall.InnerText = "Get Tree";
            btnCall.Attributes.Add("OnClick", "javascript:DisplayTree();");
            this.Controls.Add(btnCall);
        }

        protected override void OnLoad(EventArgs e)
        ...{
            if ((this.Page != null) && !this.Page.IsCallback)
            ...{

                try
                ...{
                   
                    ClientScriptManager manager = this.Page.ClientScript;

                    string temp =
                        manager.GetCallbackEventReference(this, "args", "OnComplete", "ctx", "OnMyError", true);

                    StringBuilder sb = new StringBuilder();

                    sb.AppendLine("function MyCallBack(args, ctx)");
                    sb.AppendLine("{");
                    sb.AppendLine("    " + temp + ";");
                    sb.AppendLine("}");

                    sb.AppendLine("function OnComplete(args, ctx)");
                    sb.AppendLine("{");
                    sb.AppendLine("    var values = args.split('/n');");
                    sb.AppendLine("    for (var n in values) {");
                    sb.AppendLine("        var node = new MyTreeNode();");
                    sb.AppendLine("        node.Id = oCurrentNode.Id + "|" + values[n];");
                    sb.AppendLine("        node.Name = values[n];");
                    sb.AppendLine("        node.Children = [];");
                    sb.AppendLine("        oCurrentNode.Children.push(node);");
                    sb.AppendLine("    }");
                    sb.AppendLine("    DisplayTree();");
                    sb.AppendLine("}");

                    sb.AppendLine("function MyTreeNode()");
                    sb.AppendLine("{");
                    sb.AppendLine("    var Id = '';");
                    sb.AppendLine("    var Name = '';");
                    sb.AppendLine("    var Children = [];");
                    sb.AppendLine("}");
                    sb.AppendLine("");
//                    sb.AppendLine("var nextId = 1;");
//                    sb.AppendLine("");
                    
                    sb.AppendLine("var oTree = new MyTreeNode();");
                    sb.AppendLine("oTree.Id = 'top';");
                    sb.AppendLine("oTree.Name = 'Top Tree';");
                    sb.AppendLine("oTree.Children = [];");
                    sb.AppendLine("");
                    sb.AppendLine("var oCurrentNode = oTree;");
                    sb.AppendLine("function DisplayTree()");
                    sb.AppendLine("{");
//                    sb.AppendLine("    alert('display tree' + document.getElementById('Panel1'));");
                    sb.AppendLine("    document.getElementById('Panel1').innerHTML = GetTreeContent(1, oTree);");
                    sb.AppendLine("}");
                    sb.AppendLine("");
                    sb.AppendLine("");
                    sb.AppendLine("function GetTreeContent(level, tree)");
                    sb.AppendLine("{");
//                    sb.AppendLine("    alert('get tree content:' + tree);");
                    sb.AppendLine("    var content = "<a href='javascript:GetTreeNodes(/"" + tree.Id + "/");'>" + tree.Name + "</a><br />";");
                    sb.AppendLine("   ");
                    sb.AppendLine("    for (var node in tree.Children)");
                    sb.AppendLine("    {");
                    sb.AppendLine("        for (var i = 0; i < level; i++) {");
                    sb.AppendLine("            content += "&nbsp;&nbsp;&nbsp;&nbsp;";");
                    sb.AppendLine("        }");
                    sb.AppendLine("        content += GetTreeContent(level + 1, tree.Children[node]);");
                    sb.AppendLine("    }");
                    sb.AppendLine("   ");
                    sb.AppendLine("    return content;");
                    sb.AppendLine("}");
                    sb.AppendLine("");
                    sb.AppendLine("function GetCurrentTreeNode(id, tree)");
                    sb.AppendLine("{");
                    sb.AppendLine("    if (tree.Id == id)");
                    sb.AppendLine("        return tree;");
                    sb.AppendLine("    for (var node in tree.Children) {");
                    sb.AppendLine("        var temp = GetCurrentTreeNode(id, tree.Children[node]);");
                    sb.AppendLine("        if (temp != null)");
                    sb.AppendLine("            return temp;");
                    sb.AppendLine("    }");
                    sb.AppendLine("    return null;");
                    sb.AppendLine("}");
                    sb.AppendLine("");
                    sb.AppendLine("function GetTreeNodes(id)");
                    sb.AppendLine("{");
                    sb.AppendLine("    oCurrentNode = GetCurrentTreeNode(id, oTree);");
//                    sb.AppendLine("    alert('oCurrentNode:' + oCurrentNode);");
                    sb.AppendLine("    MyCallBack(id);");
                    sb.AppendLine("}");
  


                    sb.AppendLine("function OnMyError(err)");
                    sb.AppendLine("{");
                    sb.AppendLine("    alert('error=' + err);");
                    sb.AppendLine("}");

                    manager.RegisterClientScriptBlock(base.GetType(), "MyCallBack", sb.ToString(), true);
                }
                catch(Exception ex)
                ...{
                    LogException(ex);
                }

                base.OnLoad(e);
            }
        }

        protected override void RenderContents(HtmlTextWriter writer)
        ...{
            EnsureChildControls();
            btnCall.RenderControl(writer);

            writer.WriteLine("<div id="Panel1">empty</div>");
        }


        Implement ICallbackEventHandler Members#region Implement ICallbackEventHandler Members

        private string mTreeContent = "None";

        public string GetCallbackResult()
        ...{
            return mTreeContent;
        }

        public void RaiseCallbackEvent(string eventArgument)
        ...{
            try
            ...{
                string[] names = eventArgument.Split('|');

                StringBuilder sb = new StringBuilder();

                if (names.Length == 1)
                ...{
                    SPWebService service = SPWebService.ContentService;

                    foreach (SPWebApplication app in service.WebApplications)
                    ...{
                        if (app.Status != SPObjectStatus.Online)
                            continue;
                        if (app.ContentDatabases.Count <= 0)
                            continue;
                        
                        sb.Append(app.AlternateUrls.GetResponseUrl(SPUrlZone.Default).Uri.ToString());
                        sb.Append(" ");
                    }

                    sb.Remove(sb.Length - 1, 1);
                    mTreeContent = sb.ToString();
                }
                else if (names.Length == 2)
                ...{
                    SPWebApplication app = SPWebApplication.Lookup(new Uri(names[1]));
                    foreach (SPContentDatabase db in app.ContentDatabases)
                    ...{
                        sb.Append(db.Name);
                        sb.Append(" ");
                    }

                    sb.Remove(sb.Length - 1, 1);
                    mTreeContent = sb.ToString();
                }
                else if (names.Length == 3)
                ...{
                    SPWebApplication app = SPWebApplication.Lookup(new Uri(names[1]));
                    foreach (SPSite site in app.Sites)
                    ...{
                        if (site.ContentDatabase.Name != names[2])
                            continue;

                        sb.Append(site.Url);
                        sb.Append(" ");
                    }

                    sb.Remove(sb.Length - 1, 1);
                    mTreeContent = sb.ToString();
                }
                else if (names.Length == 4)
                ...{
                    SPSite site = new SPSite(names[3]);
                    foreach (SPWeb web in site.AllWebs)
                    ...{
                        if (web.Name == "")
                            sb.Append(".");
                        else 
                            sb.Append(web.Name);
                        sb.Append(" ");
                    }

                    sb.Remove(sb.Length - 1, 1);
                    mTreeContent = sb.ToString();
                }
                else
                ...{
                    mTreeContent = "node1 node2 node3";
                }
            }
            catch(Exception ex)
            ...{
                LogException(ex);
            }
        }

        private void LogException(Exception ex)
        ...{
            mTreeContent = "Error:" + ex.Message + " " + ex.StackTrace;
        }
        #endregion
    }
}