RouteDebugger分析
RouteDebugger的介绍 http://www.cnblogs.com/suizhikuo/archive/2012/07/25/2608889.html
2.RouteDebugger结构，一共有5个文件，将逐一解释每个文件的作用
RouteDebug.cs
using System.Web.Routing; namespace RouteDebug { public class DebugRoute : Route { static readonly DebugRoute singleton = new DebugRoute(); public static DebugRoute Singleton { get { return singleton; } } private DebugRoute() : base("{*catchall}", new DebugRouteHandler()) { } } }
全局单例的DebugRoute,构造函数传入了DebugRouteHandler。
DebugRouteHandler.cs
using System.Web; using System.Web.Routing; namespace RouteDebug { public class DebugRouteHandler : IRouteHandler { public IHttpHandler GetHttpHandler(RequestContext requestContext) { return new DebugHttpHandler(); } } }
核心都在DebugHttpHandler最后再解释。
PreApplicationStart.cs
using System; using System.Configuration; using System.Web; using RouteDebug; [assembly: PreApplicationStartMethod(typeof(PreApplicationStart), "Start")] namespace RouteDebug { public class PreApplicationStart { public static void Start() { bool enabled = Convert.ToBoolean(ConfigurationManager.AppSettings["RouteDebugger:Enabled"]); if (enabled) { Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(RouteDebuggerHttpModule)); } } } }
项目启动时利用DynamicModuleUtility根据Webconfig配置动态的注册RouteDebuggerHttpModule.
RouteDebuggerHttpModule.cs
namespace RouteDebug { public class RouteDebuggerHttpModule : IHttpModule { public void Init(HttpApplication context) { context.EndRequest += OnEndRequest; context.BeginRequest += OnBeginRequest; } static void OnBeginRequest(object sender, System.EventArgs e) { if (RouteTable.Routes.Last() != DebugRoute.Singleton) { RouteTable.Routes.Add(DebugRoute.Singleton); } } static void OnEndRequest(object sender, System.EventArgs e) { var handler = new DebugHttpHandler(); handler.ProcessRequest(HttpContext.Current); } public void Dispose() { } } }
OnBeginRequest向路由表添加DebugRoute.
OnEndRequest输出RouteDebugger信息.
DebugHttpHandler.cs
using System; using System.Collections.Generic; using System.Reflection; using System.Web; using System.Web.Hosting; using System.Web.Routing; namespace RouteDebug { public class DebugHttpHandler : IHttpHandler { readonly VirtualPathProvider _virtualPathProvider; public DebugHttpHandler() : this(null) { } public DebugHttpHandler(VirtualPathProvider virtualPathProvider) { _virtualPathProvider = virtualPathProvider ?? HostingEnvironment.VirtualPathProvider; } public void ProcessRequest(HttpContext context) { var request = context.Request; if (!IsRoutedRequest(request) || context.Response.ContentType == null || !context.Response.ContentType.Equals("text/html", StringComparison.OrdinalIgnoreCase)) { return; } string generatedUrlInfo = string.Empty; var requestContext = request.RequestContext; if (request.QueryString.Count > 0) { var rvalues = new RouteValueDictionary(); foreach (string key in request.QueryString.Keys) { if (key != null) { rvalues.Add(key, request.QueryString[key]); } } var vpd = RouteTable.Routes.GetVirtualPath(requestContext, rvalues); if (vpd != null) { generatedUrlInfo = "<p><label style=\"font-weight: bold; font-size: 1.1em;\">Generated URL</label>: "; generatedUrlInfo += "<strong style=\"color: #00a;\">" + vpd.VirtualPath + "</strong>"; var vpdRoute = vpd.Route as Route; if (vpdRoute != null) { generatedUrlInfo += " using the route \"" + vpdRoute.Url + "\"</p>"; } } } const string htmlFormat = @"<html> <div id=""haackroutedebugger"" style=""background-color: #fff; padding-bottom: 10px;""> <style> #haackroutedebugger, #haackroutedebugger td, #haackroutedebugger th {{background-color: #fff; font-family: verdana, helvetica, san-serif; font-size: small;}} #haackroutedebugger tr.header td, #haackroutedebugger tr.header th {{background-color: #ffc;}} </style> <hr style=""width: 100%; border: solid 1px #000; margin:0; padding:0;"" /> <h1 style=""margin: 0; padding: 4px; border-bottom: solid 1px #bbb; padding-left: 10px; font-size: 1.2em; background-color: #ffc;"">Route Debugger</h1> <div id=""main"" style=""margin-top:0; padding: 0 10px;""> <p style=""font-size: .9em; padding-top:0""> Type in a url in the address bar to see which defined routes match it. A {{*catchall}} route is added to the list of routes automatically in case none of your routes match. </p> <p style=""font-size: .9em;""> To generate URLs using routing, supply route values via the query string. example: <code>http://localhost:14230/?id=123</code> </p> <p><label style=""font-weight: bold; font-size: 1.1em;"">Matched Route</label>: {1}</p> {5} <div style=""float: left;""> <table border=""1"" cellpadding=""3"" cellspacing=""0"" width=""300""> <caption style=""font-weight: bold;"">Route Data</caption> <tr class=""header""><th>Key</th><th>Value</th></tr> {0} </table> </div> <div style=""float: left; margin-left: 10px;""> <table border=""1"" cellpadding=""3"" cellspacing=""0"" width=""300""> <caption style=""font-weight: bold;"">Data Tokens</caption> <tr class=""header""><th>Key</th><th>Value</th></tr> {4} </table> </div> <hr style=""clear: both;"" /> <table border=""1"" cellpadding=""3"" cellspacing=""0""> <caption style=""font-weight: bold;"">All Routes</caption> <tr class=""header""> <th>Matches Current Request</th> <th>Url</th> <th>Defaults</th> <th>Constraints</th> <th>DataTokens</th> </tr> {2} </table> <hr /> <h3>Current Request Info</h3> <p> AppRelativeCurrentExecutionFilePath is the portion of the request that Routing acts on. </p> <p><strong>AppRelativeCurrentExecutionFilePath</strong>: {3}</p> </div> </div>"; string routeDataRows = string.Empty; var routeData = requestContext.RouteData; var routeValues = routeData.Values; var matchedRouteBase = routeData.Route; string routes = string.Empty; using (RouteTable.Routes.GetReadLock()) { foreach (var routeBase in RouteTable.Routes) { bool matchesCurrentRequest = (routeBase.GetRouteData(requestContext.HttpContext) != null); string matchText = string.Format(@"<span{0}>{1}</span>", BoolStyle(matchesCurrentRequest), matchesCurrentRequest); string url = "n/a"; string defaults = "n/a"; string constraints = "n/a"; string dataTokens = "n/a"; Route route = CastRoute(routeBase); if (route != null) { url = route.Url; defaults = FormatDictionary(route.Defaults); constraints = FormatDictionary(route.Constraints); dataTokens = FormatDictionary(route.DataTokens); } routes += string.Format(@"<tr><td>{0}</td><td>{1}</td><td>{2}</td><td>{3}</td><td>{4}</td></tr>" , matchText , url , defaults , constraints , dataTokens); } } string matchedRouteUrl = "n/a"; string dataTokensRows = ""; if (!(matchedRouteBase is DebugRoute)) { foreach (string key in routeValues.Keys) { routeDataRows += string.Format("\t<tr><td>{0}</td><td>{1} </td></tr>", key, routeValues[key]); } foreach (string key in routeData.DataTokens.Keys) { dataTokensRows += string.Format("\t<tr><td>{0}</td><td>{1} </td></tr>", key, routeData.DataTokens[key]); } var matchedRoute = matchedRouteBase as Route; if (matchedRoute != null) matchedRouteUrl = matchedRoute.Url; } else { matchedRouteUrl = string.Format("<strong{0}>NO MATCH!</strong>", BoolStyle(false)); } context.Response.Write(string.Format(htmlFormat , routeDataRows , matchedRouteUrl , routes , request.AppRelativeCurrentExecutionFilePath , dataTokensRows , generatedUrlInfo)); } private Route CastRoute(RouteBase routeBase) { var route = routeBase as Route; if (route == null) { // cheat! // TODO: Create an interface for self reporting routes. var type = routeBase.GetType(); var property = type.GetProperty("__DebugRoute", BindingFlags.NonPublic | BindingFlags.Instance); if (property != null) { route = property.GetValue(routeBase, null) as Route; } } return route; } private static string FormatDictionary(IDictionary<string, object> values) { if (values == null) return "(null)"; if (values.Count == 0) { return "(empty)"; } string display = string.Empty; foreach (string key in values.Keys) { display += string.Format("{0} = {1}, ", key, FormatObject(values[key])); } if (display.EndsWith(", ")) display = display.Substring(0, display.Length - 2); return display; } private static string FormatObject(object value) { if (value == null) { return "(null)"; } var values = value as object[]; if (values != null) { return string.Join(", ", values); } var dictionaryValues = value as IDictionary<string, object>; if (dictionaryValues != null) { return FormatDictionary(dictionaryValues); } if (value.GetType().Name == "UrlParameter") { return "UrlParameter.Optional"; } return value.ToString(); } private static string BoolStyle(bool boolean) { if (boolean) return " style=\"color: #0c0\""; return " style=\"color: #c00\""; } private bool IsRoutedRequest(HttpRequest request) { string path = request.AppRelativeCurrentExecutionFilePath; if (path != "~/" && (_virtualPathProvider.FileExists(path) || _virtualPathProvider.DirectoryExists(path))) { return false; } return true; } public bool IsReusable { get { return true; } } } }
IHttpHandler接口肯定都不陌生，有两个地方会调用到ProcessRequest方法。一是RouteDebuggerHttpModule的EndRequest方法。二是匹配到DebugRoute，DebugRoute加在了路由表的最后，没有匹配到任何的Route的时候就会返回DebugRoute。 所以这个时候就会输出两次ProcessRequest. 这是RouteDebugger的核心，循环RouteTable.Routes判断是否匹并且输出。