asp.net mvc源码分析-Route的GetRouteData
我知道Route这里东西应该算路由，这里把它放到mvc里面有些不怎么合适，但是我想大家多数遇到路由都是在mvc的时候吧.首先我们还是来看看GetRouteData方法吧
[csharp] public override RouteData GetRouteData(HttpContextBase httpContext) { string virtualPath = httpContext.Request.AppRelativeCurrentExecutionFilePath.Substring(2) + httpContext.Request.PathInfo; RouteValueDictionary values = this._parsedRoute.Match(virtualPath, this.Defaults); if (values == null) { return null; } RouteData data = new RouteData(this, this.RouteHandler); if (!this.ProcessConstraints(httpContext, values, RouteDirection.IncomingRequest)) { return null; } foreach (KeyValuePair<string, object> pair in values) { data.Values.Add(pair.Key, pair.Value); } if (this.DataTokens != null) { foreach (KeyValuePair<string, object> pair2 in this.DataTokens) { data.DataTokens[pair2.Key] = pair2.Value; } } return data; } public override RouteData GetRouteData(HttpContextBase httpContext) { string virtualPath = httpContext.Request.AppRelativeCurrentExecutionFilePath.Substring(2) + httpContext.Request.PathInfo; RouteValueDictionary values = this._parsedRoute.Match(virtualPath, this.Defaults); if (values == null) { return null; } RouteData data = new RouteData(this, this.RouteHandler); if (!this.ProcessConstraints(httpContext, values, RouteDirection.IncomingRequest)) { return null; } foreach (KeyValuePair<string, object> pair in values) { data.Values.Add(pair.Key, pair.Value); } if (this.DataTokens != null) { foreach (KeyValuePair<string, object> pair2 in this.DataTokens) { data.DataTokens[pair2.Key] = pair2.Value; } } return data; }
我还是沿用以前的思路，已一个demo来便说明吧，现在假设我的路由信息是：
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.IgnoreRoute("{*favicon}", new { favicon = @"(.*/)?favicon.ico(/.*)?" });
routes.MapRoute(
"Default", // 路由名称
"{controller}/{action}/{id}", // 带有参数的 URL
new { controller = "Home", action = "Index", id = UrlParameter.Optional }, // 参数默认值
new { controller="([A-Za-z])*" },
new string[] { "MvcApp.Controllers" }
);
我们知道httpContext.Request.AppRelativeCurrentExecutionFilePath的返回值都是以~/打头的，这里httpContext.Request.PathInfo为空，多数情况下该属性也是空的，所以这里的virtualPath=Home/index。
有关MapRoute的代码可以参照
[csharp] public static Route MapRoute(this RouteCollection routes, string name, string url, object defaults, object constraints, string[] namespaces) { if (routes == null) { throw new ArgumentNullException("routes"); } if (url == null) { throw new ArgumentNullException("url"); } Route route = new Route(url, new MvcRouteHandler()) { Defaults = new RouteValueDictionary(defaults), Constraints = new RouteValueDictionary(constraints), DataTokens = new RouteValueDictionary() }; if ((namespaces != null) && (namespaces.Length > 0)) { route.DataTokens["Namespaces"] = namespaces; } routes.Add(name, route); return route; } public static Route MapRoute(this RouteCollection routes, string name, string url, object defaults, object constraints, string[] namespaces) { if (routes == null) { throw new ArgumentNullException("routes"); } if (url == null) { throw new ArgumentNullException("url"); } Route route = new Route(url, new MvcRouteHandler()) { Defaults = new RouteValueDictionary(defaults), Constraints = new RouteValueDictionary(constraints), DataTokens = new RouteValueDictionary() }; if ((namespaces != null) && (namespaces.Length > 0)) { route.DataTokens["Namespaces"] = namespaces; } routes.Add(name, route); return route; }
首先调用_parsedRoute.Match(virtualPath, this.Defaults)获取一个RouteValueDictionary ，至于这个方法的具体实现放到后面来说，然后实例化一个RouteData ，并且把先前的RouteValueDictionary的值添加到先前实例化的 RouteData中，如果DataTokens有元素的话也加入到RouteData的DataTokens中来。不过这个过程有个约束的处理
if (!this.ProcessConstraints(httpContext, values, RouteDirection.IncomingRequest)) { return null; }
其中RouteDirection的定义如下：
1 public enum RouteDirection 2 { 3 IncomingRequest, 4 UrlGeneration 5 }
约束检查失败而返回null，现在我们来看看ProcessConstraints方法：
private bool ProcessConstraints(HttpContextBase httpContext, RouteValueDictionary values, RouteDirection routeDirection) { if (this.Constraints != null) { foreach (KeyValuePair<string, object> pair in this.Constraints) { if (!this.ProcessConstraint(httpContext, pair.Value, pair.Key, values, routeDirection)) { return false; } } } return true; }
如果Constraints有元素，依次检查每个成员，检查方法主要是调用ProcessConstraint方法，
[csharp] protected virtual bool ProcessConstraint(HttpContextBase httpContext, object constraint, string parameterName, RouteValueDictionary values, RouteDirection routeDirection) { object obj2; IRouteConstraint constraint2 = constraint as IRouteConstraint; if (constraint2 != null) { return constraint2.Match(httpContext, this, parameterName, values, routeDirection); } string str = constraint as string; if (str == null) { throw new InvalidOperationException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_ValidationMustBeStringOrCustomConstraint"), new object[] { parameterName, this.Url })); } values.TryGetValue(parameterName, out obj2); string input = Convert.ToString(obj2, CultureInfo.InvariantCulture); string pattern = "^(" + str + ")$"; return Regex.IsMatch(input, pattern, RegexOptions.CultureInvariant | RegexOptions.Compiled | RegexOptions.IgnoreCase); } protected virtual bool ProcessConstraint(HttpContextBase httpContext, object constraint, string parameterName, RouteValueDictionary values, RouteDirection routeDirection) { object obj2; IRouteConstraint constraint2 = constraint as IRouteConstraint; if (constraint2 != null) { return constraint2.Match(httpContext, this, parameterName, values, routeDirection); } string str = constraint as string; if (str == null) { throw new InvalidOperationException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_ValidationMustBeStringOrCustomConstraint"), new object[] { parameterName, this.Url })); } values.TryGetValue(parameterName, out obj2); string input = Convert.ToString(obj2, CultureInfo.InvariantCulture); string pattern = "^(" + str + ")$"; return Regex.IsMatch(input, pattern, RegexOptions.CultureInvariant | RegexOptions.Compiled | RegexOptions.IgnoreCase); }
这里首先检查我们的约束类型，如果它是IRouteConstraint那么就直接调用它的Match方法，约束不是IRouteConstraint那么就转化为字符串，再把约束验证的值从RouteValueDictionary 中取出来转化为字符串，最后在用正则表达式来验证我们的值是否通过。
好，现在让我们来看看this._parsedRoute.Match(virtualPath, this.Defaults);这个方法是然后获取RouteValueDictionary的：
[csharp] public RouteValueDictionary Match(string virtualPath, RouteValueDictionary defaultValues) { IList<string> source = RouteParser.SplitUrlToPathSegmentStrings(virtualPath); if (defaultValues == null) { defaultValues = new RouteValueDictionary(); } RouteValueDictionary matchedValues = new RouteValueDictionary(); bool flag = false; bool flag2 = false; for (int i = 0; i < this.PathSegments.Count; i++) { PathSegment segment = this.PathSegments[i]; if (source.Count <= i) { flag = true; } string a = flag ? null : source[i]; if (segment is SeparatorPathSegment) { if (!flag && !string.Equals(a, "/", StringComparison.Ordinal)) { return null; } } else { ContentPathSegment contentPathSegment = segment as ContentPathSegment; if (contentPathSegment != null) { if (contentPathSegment.IsCatchAll) { this.MatchCatchAll(contentPathSegment, source.Skip<string>(i), defaultValues, matchedValues); flag2 = true; } else if (!this.MatchContentPathSegment(contentPathSegment, a, defaultValues, matchedValues)) { return null; } } } } if (!flag2 && (this.PathSegments.Count < source.Count)) { for (int j = this.PathSegments.Count; j < source.Count; j++) { if (!RouteParser.IsSeparator(source[j])) { return null; } } } if (defaultValues != null) { foreach (KeyValuePair<string, object> pair in defaultValues) { if (!matchedValues.ContainsKey(pair.Key)) { matchedValues.Add(pair.Key, pair.Value); } } } return matchedValues; } public RouteValueDictionary Match(string virtualPath, RouteValueDictionary defaultValues) { IList<string> source = RouteParser.SplitUrlToPathSegmentStrings(virtualPath); if (defaultValues == null) { defaultValues = new RouteValueDictionary(); } RouteValueDictionary matchedValues = new RouteValueDictionary(); bool flag = false; bool flag2 = false; for (int i = 0; i < this.PathSegments.Count; i++) { PathSegment segment = this.PathSegments[i]; if (source.Count <= i) { flag = true; } string a = flag ? null : source[i]; if (segment is SeparatorPathSegment) { if (!flag && !string.Equals(a, "/", StringComparison.Ordinal)) { return null; } } else { ContentPathSegment contentPathSegment = segment as ContentPathSegment; if (contentPathSegment != null) { if (contentPathSegment.IsCatchAll) { this.MatchCatchAll(contentPathSegment, source.Skip<string>(i), defaultValues, matchedValues); flag2 = true; } else if (!this.MatchContentPathSegment(contentPathSegment, a, defaultValues, matchedValues)) { return null; } } } } if (!flag2 && (this.PathSegments.Count < source.Count)) { for (int j = this.PathSegments.Count; j < source.Count; j++) { if (!RouteParser.IsSeparator(source[j])) { return null; } } } if (defaultValues != null) { foreach (KeyValuePair<string, object> pair in defaultValues) { if (!matchedValues.ContainsKey(pair.Key)) { matchedValues.Add(pair.Key, pair.Value); } } } return matchedValues; }
这里RouteParser的SplitUrlToPathSegmentStrings方法很简单，就是把url字符串按照”/“来分割
[csharp] view plaincopyprint?internal static IList<string> SplitUrlToPathSegmentStrings(string url) { List<string> list = new List<string>(); if (!string.IsNullOrEmpty(url)) { int index; for (int i = 0; i < url.Length; i = index + 1) { index = url.IndexOf('/', i); if (index == -1) { string str = url.Substring(i); if (str.Length > 0) { list.Add(str); } return list; } string item = url.Substring(i, index - i); if (item.Length > 0) { list.Add(item); } list.Add("/"); } } return list; } internal static IList<string> SplitUrlToPathSegmentStrings(string url) { List<string> list = new List<string>(); if (!string.IsNullOrEmpty(url)) { int index; for (int i = 0; i < url.Length; i = index + 1) { index = url.IndexOf('/', i); if (index == -1) { string str = url.Substring(i); if (str.Length > 0) { list.Add(str); } return list; } string item = url.Substring(i, index - i); if (item.Length > 0) { list.Add(item); } list.Add("/"); } } return list; }
所以Match方法中的source 是成员是很好明白的，我的示例中它的值是：
在ParsedRoute的Match方法中用到了一个PathSegments属性。该属性定义为：private IList<PathSegment> PathSegments { get; set; }真正该改属性复制的是ParsedRoute的构造函数。而Route中的_parsedRoute的获取是在Url属性中
public string Url { get { return (this._url ?? string.Empty); } set { this._parsedRoute = RouteParser.Parse(value); this._url = value; } }
在我们这个例子中url的value={controller}/{action}/{id}。
其中RouteParser的Parse方法如下：
[csharp] public static ParsedRoute Parse(string routeUrl) { if (routeUrl == null) { routeUrl = string.Empty; } if ((routeUrl.StartsWith("~", StringComparison.Ordinal) || routeUrl.StartsWith("/", StringComparison.Ordinal)) || (routeUrl.IndexOf('?') != -1)) { throw new ArgumentException(SR.GetString("Route_InvalidRouteUrl"), "routeUrl"); } IList<string> pathSegments = SplitUrlToPathSegmentStrings(routeUrl); Exception exception = ValidateUrlParts(pathSegments); if (exception != null) { throw exception; } return new ParsedRoute(SplitUrlToPathSegments(pathSegments)); } public static ParsedRoute Parse(string routeUrl) { if (routeUrl == null) { routeUrl = string.Empty; } if ((routeUrl.StartsWith("~", StringComparison.Ordinal) || routeUrl.StartsWith("/", StringComparison.Ordinal)) || (routeUrl.IndexOf('?') != -1)) { throw new ArgumentException(SR.GetString("Route_InvalidRouteUrl"), "routeUrl"); } IList<string> pathSegments = SplitUrlToPathSegmentStrings(routeUrl); Exception exception = ValidateUrlParts(pathSegments); if (exception != null) { throw exception; } return new ParsedRoute(SplitUrlToPathSegments(pathSegments)); }
在这里我们知道url不能以~ /打头，也不能含有？。这里的pathSegments也很好理解，其值：
这里的ValidateUrlParts主要就是验证这里的pathSegments集合，ValidateUrlParts这里的具体是怎么验证的很是复杂，这里就忽略了它吧。
有关SplitUrlToPathSegments的方法比较复杂，分为两部分，把urlParts中的"/" 变成SeparatorPathSegment对象作为站位，像{controller}这样转换为ContentPathSegment对象，其中它的subsegments是一个List<PathSubsegment>实例，
[csharp] private static IList<PathSegment> SplitUrlToPathSegments(IList<string> urlParts) { List<PathSegment> list = new List<PathSegment>(); foreach (string str in urlParts) { if (IsSeparator(str)) { list.Add(new SeparatorPathSegment()); } else { Exception exception; IList<PathSubsegment> subsegments = ParseUrlSegment(str, out exception); list.Add(new ContentPathSegment(subsegments)); } } return list; } internal static bool IsSeparator(string s) { return string.Equals(s, "/", StringComparison.Ordinal); } private static IList<PathSubsegment> ParseUrlSegment(string segment, out Exception exception) { int startIndex = 0; List<PathSubsegment> list = new List<PathSubsegment>(); while (startIndex < segment.Length) { int num2 = IndexOfFirstOpenParameter(segment, startIndex); if (num2 == -1) { string str = GetLiteral(segment.Substring(startIndex)); if (str == null) { exception = new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_MismatchedParameter"), new object[] { segment }), "routeUrl"); return null; } if (str.Length > 0) { list.Add(new LiteralSubsegment(str)); } break; } int index = segment.IndexOf('}', num2 + 1); if (index == -1) { exception = new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_MismatchedParameter"), new object[] { segment }), "routeUrl"); return null; } string literal = GetLiteral(segment.Substring(startIndex, num2 - startIndex)); if (literal == null) { exception = new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_MismatchedParameter"), new object[] { segment }), "routeUrl"); return null; } if (literal.Length > 0) { list.Add(new LiteralSubsegment(literal)); } string parameterName = segment.Substring(num2 + 1, (index - num2) - 1); list.Add(new ParameterSubsegment(parameterName)); startIndex = index + 1; } exception = null; return list; } private static int IndexOfFirstOpenParameter(string segment, int startIndex) { while (true) { startIndex = segment.IndexOf('{', startIndex); if (startIndex == -1) { return -1; } if (((startIndex + 1) == segment.Length) || (((startIndex + 1) < segment.Length) && (segment[startIndex + 1] != '{'))) { return startIndex; } startIndex += 2; } } private static string GetLiteral(string segmentLiteral) { string str = segmentLiteral.Replace("{{", "").Replace("}}", ""); if (!str.Contains("{") && !str.Contains("}")) { return segmentLiteral.Replace("{{", "{").Replace("}}", "}"); } return null; } internal sealed class LiteralSubsegment : PathSubsegment { // Methods public LiteralSubsegment(string literal) { this.Literal = literal; } // Properties public string Literal { get; private set; } } internal sealed class ParameterSubsegment : PathSubsegment { // Methods public ParameterSubsegment(string parameterName) { if (parameterName.StartsWith("*", StringComparison.Ordinal)) { this.ParameterName = parameterName.Substring(1); this.IsCatchAll = true; } else { this.ParameterName = parameterName; } } // Properties public bool IsCatchAll { get; private set; } public string ParameterName { get; private set; } } internal sealed class ContentPathSegment : PathSegment { // Methods public ContentPathSegment(IList<PathSubsegment> subsegments) { this.Subsegments = subsegments; } // Properties public bool IsCatchAll { get { return this.Subsegments.Any<PathSubsegment>(seg => ((seg is ParameterSubsegment) && ((ParameterSubsegment)seg).IsCatchAll)); } } public IList<PathSubsegment> Subsegments { get; private set; } } private static IList<PathSegment> SplitUrlToPathSegments(IList<string> urlParts) { List<PathSegment> list = new List<PathSegment>(); foreach (string str in urlParts) { if (IsSeparator(str)) { list.Add(new SeparatorPathSegment()); } else { Exception exception; IList<PathSubsegment> subsegments = ParseUrlSegment(str, out exception); list.Add(new ContentPathSegment(subsegments)); } } return list; } internal static bool IsSeparator(string s) { return string.Equals(s, "/", StringComparison.Ordinal); } private static IList<PathSubsegment> ParseUrlSegment(string segment, out Exception exception) { int startIndex = 0; List<PathSubsegment> list = new List<PathSubsegment>(); while (startIndex < segment.Length) { int num2 = IndexOfFirstOpenParameter(segment, startIndex); if (num2 == -1) { string str = GetLiteral(segment.Substring(startIndex)); if (str == null) { exception = new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_MismatchedParameter"), new object[] { segment }), "routeUrl"); return null; } if (str.Length > 0) { list.Add(new LiteralSubsegment(str)); } break; } int index = segment.IndexOf('}', num2 + 1); if (index == -1) { exception = new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_MismatchedParameter"), new object[] { segment }), "routeUrl"); return null; } string literal = GetLiteral(segment.Substring(startIndex, num2 - startIndex)); if (literal == null) { exception = new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_MismatchedParameter"), new object[] { segment }), "routeUrl"); return null; } if (literal.Length > 0) { list.Add(new LiteralSubsegment(literal)); } string parameterName = segment.Substring(num2 + 1, (index - num2) - 1); list.Add(new ParameterSubsegment(parameterName)); startIndex = index + 1; } exception = null; return list; } private static int IndexOfFirstOpenParameter(string segment, int startIndex) { while (true) { startIndex = segment.IndexOf('{', startIndex); if (startIndex == -1) { return -1; } if (((startIndex + 1) == segment.Length) || (((startIndex + 1) < segment.Length) && (segment[startIndex + 1] != '{'))) { return startIndex; } startIndex += 2; } } private static string GetLiteral(string segmentLiteral) { string str = segmentLiteral.Replace("{{", "").Replace("}}", ""); if (!str.Contains("{") && !str.Contains("}")) { return segmentLiteral.Replace("{{", "{").Replace("}}", "}"); } return null; } internal sealed class LiteralSubsegment : PathSubsegment { // Methods public LiteralSubsegment(string literal) { this.Literal = literal; } // Properties public string Literal { get; private set; } } internal sealed class ParameterSubsegment : PathSubsegment { // Methods public ParameterSubsegment(string parameterName) { if (parameterName.StartsWith("*", StringComparison.Ordinal)) { this.ParameterName = parameterName.Substring(1); this.IsCatchAll = true; } else { this.ParameterName = parameterName; } } // Properties public bool IsCatchAll { get; private set; } public string ParameterName { get; private set; } } internal sealed class ContentPathSegment : PathSegment { // Methods public ContentPathSegment(IList<PathSubsegment> subsegments) { this.Subsegments = subsegments; } // Properties public bool IsCatchAll { get { return this.Subsegments.Any<PathSubsegment>(seg => ((seg is ParameterSubsegment) && ((ParameterSubsegment)seg).IsCatchAll)); } } public IList<PathSubsegment> Subsegments { get; private set; } }
ParseUrlSegment方法主要就是获取代码是：
string parameterName = segment.Substring(num2 + 1, (index - num2) - 1); list.Add(new ParameterSubsegment(parameterName));
例如我们传进来的字符串是{controller}，那么这里parameterName就会处理为controller。如果传入的参数没有{、}如Channel，那么ParseUrlSegment将处理为
if (str.Length > 0) { list.Add(new LiteralSubsegment(str)); } break;
现在是时候回到ParsedRoute的Match方法了，首先我们来看看这个方法用到的PathSegments是个什么东东，我的url是{controller}/{action}/{id}它对应的PathSegments如图：
着了我们看看几次循环的主要变量取值：
当前ContentPathSegment的IsCatchAll为false。那么我们现在主要关心的是MatchContentPathSegment方法了
[csharp] private bool MatchContentPathSegment(ContentPathSegment routeSegment, string requestPathSegment, RouteValueDictionary defaultValues, RouteValueDictionary matchedValues) { if (string.IsNullOrEmpty(requestPathSegment)) { if (routeSegment.Subsegments.Count <= 1) { object obj2; ParameterSubsegment subsegment = routeSegment.Subsegments[0] as ParameterSubsegment; if (subsegment == null) { return false; } if (defaultValues.TryGetValue(subsegment.ParameterName, out obj2)) { matchedValues.Add(subsegment.ParameterName, obj2); return true; } } return false; } int length = requestPathSegment.Length; int num2 = routeSegment.Subsegments.Count - 1; ParameterSubsegment subsegment2 = null; LiteralSubsegment subsegment3 = null; while (num2 >= 0) { int num3 = length; ParameterSubsegment subsegment4 = routeSegment.Subsegments[num2] as ParameterSubsegment; if (subsegment4 != null) { subsegment2 = subsegment4; } else { LiteralSubsegment subsegment5 = routeSegment.Subsegments[num2] as LiteralSubsegment; if (subsegment5 != null) { subsegment3 = subsegment5; int startIndex = length - 1; if (subsegment2 != null) { startIndex--; } if (startIndex < 0) { return false; } int num5 = requestPathSegment.LastIndexOf(subsegment5.Literal, startIndex, StringComparison.OrdinalIgnoreCase); if (num5 == -1) { return false; } if ((num2 == (routeSegment.Subsegments.Count - 1)) && ((num5 + subsegment5.Literal.Length) != requestPathSegment.Length)) { return false; } num3 = num5; } } if ((subsegment2 != null) && (((subsegment3 != null) && (subsegment4 == null)) || (num2 == 0))) { int num6; int num7; if (subsegment3 == null) { if (num2 == 0) { num6 = 0; } else { num6 = num3 + subsegment3.Literal.Length; } num7 = length; } else if ((num2 == 0) && (subsegment4 != null)) { num6 = 0; num7 = length; } else { num6 = num3 + subsegment3.Literal.Length; num7 = length - num6; } string str = requestPathSegment.Substring(num6, num7); if (string.IsNullOrEmpty(str)) { return false; } matchedValues.Add(subsegment2.ParameterName, str); subsegment2 = null; subsegment3 = null; } length = num3; num2--; } if (length != 0) { return (routeSegment.Subsegments[0] is ParameterSubsegment); } return true; } private bool MatchContentPathSegment(ContentPathSegment routeSegment, string requestPathSegment, RouteValueDictionary defaultValues, RouteValueDictionary matchedValues) { if (string.IsNullOrEmpty(requestPathSegment)) { if (routeSegment.Subsegments.Count <= 1) { object obj2; ParameterSubsegment subsegment = routeSegment.Subsegments[0] as ParameterSubsegment; if (subsegment == null) { return false; } if (defaultValues.TryGetValue(subsegment.ParameterName, out obj2)) { matchedValues.Add(subsegment.ParameterName, obj2); return true; } } return false; } int length = requestPathSegment.Length; int num2 = routeSegment.Subsegments.Count - 1; ParameterSubsegment subsegment2 = null; LiteralSubsegment subsegment3 = null; while (num2 >= 0) { int num3 = length; ParameterSubsegment subsegment4 = routeSegment.Subsegments[num2] as ParameterSubsegment; if (subsegment4 != null) { subsegment2 = subsegment4; } else { LiteralSubsegment subsegment5 = routeSegment.Subsegments[num2] as LiteralSubsegment; if (subsegment5 != null) { subsegment3 = subsegment5; int startIndex = length - 1; if (subsegment2 != null) { startIndex--; } if (startIndex < 0) { return false; } int num5 = requestPathSegment.LastIndexOf(subsegment5.Literal, startIndex, StringComparison.OrdinalIgnoreCase); if (num5 == -1) { return false; } if ((num2 == (routeSegment.Subsegments.Count - 1)) && ((num5 + subsegment5.Literal.Length) != requestPathSegment.Length)) { return false; } num3 = num5; } } if ((subsegment2 != null) && (((subsegment3 != null) && (subsegment4 == null)) || (num2 == 0))) { int num6; int num7; if (subsegment3 == null) { if (num2 == 0) { num6 = 0; } else { num6 = num3 + subsegment3.Literal.Length; } num7 = length; } else if ((num2 == 0) && (subsegment4 != null)) { num6 = 0; num7 = length; } else { num6 = num3 + subsegment3.Literal.Length; num7 = length - num6; } string str = requestPathSegment.Substring(num6, num7); if (string.IsNullOrEmpty(str)) { return false; } matchedValues.Add(subsegment2.ParameterName, str); subsegment2 = null; subsegment3 = null; } length = num3; num2--; } if (length != 0) { return (routeSegment.Subsegments[0] is ParameterSubsegment); } return true; }
这个方法就是真正把路由参数和路由的值给关联起来，如果参数requestPathSegment为null则参数值从defaultValues中获取，
if (defaultValues.TryGetValue(subsegment.ParameterName, out obj2)) { matchedValues.Add(subsegment.ParameterName, obj2); return true; }
否则从我们传递进来的requestPathSegment获取。
string str = requestPathSegment.Substring(num6, num7); if (string.IsNullOrEmpty(str)) { return false; } matchedValues.Add(subsegment2.ParameterName, str);
Match方法在结束之前会检查我们的defaultValues字典，把defaultValues中的key（matchedValues不存在对应的key）加到matchedValues中来。整个match方法及结束了，结合前面的东西我们也就可以明白Route类的GetRouteData方法了。
为了跟好的理解上面个方法，我这里再举一个demo：
路由信息： routes.MapRoute("Default", "{ChannelName}/{action}", new { controller = "Home", action = "Index" });
调用Match方法的 virtualPath=men/index，
source取值：
PathSegments取值：
至于Match方法中的有一种路径是调用MatchCatchAll方法，
[csharp] private void MatchCatchAll(ContentPathSegment contentPathSegment, IEnumerable<string> remainingRequestSegments, RouteValueDictionary defaultValues, RouteValueDictionary matchedValues) { object obj2; string str = string.Join(string.Empty, remainingRequestSegments.ToArray<string>()); ParameterSubsegment subsegment = contentPathSegment.Subsegments[0] as ParameterSubsegment; if (str.Length > 0) { obj2 = str; } else { defaultValues.TryGetValue(subsegment.ParameterName, out obj2); } matchedValues.Add(subsegment.ParameterName, obj2); } private void MatchCatchAll(ContentPathSegment contentPathSegment, IEnumerable<string> remainingRequestSegments, RouteValueDictionary defaultValues, RouteValueDictionary matchedValues) { object obj2; string str = string.Join(string.Empty, remainingRequestSegments.ToArray<string>()); ParameterSubsegment subsegment = contentPathSegment.Subsegments[0] as ParameterSubsegment; if (str.Length > 0) { obj2 = str; } else { defaultValues.TryGetValue(subsegment.ParameterName, out obj2); } matchedValues.Add(subsegment.ParameterName, obj2); }
它要求contentPathSegment.IsCatchAll为true。从 ParameterSubsegment类的定义可以知道当且仅当传进来parameterName以*打头才是True。parameterName是从url中来的，也就是说url中要含有*，IsCatchAll才为true。在前面提到的ValidateUrlParts方法会验证url的，其主要代码如下：
private static Exception ValidateUrlParts(IList<string> pathSegments) { HashSet<string> usedParameterNames = new HashSet<string>(StringComparer.OrdinalIgnoreCase); bool? nullable = null; bool flag = false; foreach (string str in pathSegments) { bool flag2; if (flag) { return new ArgumentException(string.Format(CultureInfo.CurrentUICulture, SR.GetString("Route_CatchAllMustBeLast"), new object[0]), "routeUrl"); } if (!flag2) { Exception exception; IList<PathSubsegment> pathSubsegments = ParseUrlSegment(str, out exception); flag = pathSubsegments.Any<PathSubsegment>(seg => (seg is ParameterSubsegment) && ((ParameterSubsegment) seg).IsCatchAll); } } return null; }
所以以上的那个MatchCatchAll执行的条件也很明显就是url中带有*号，并且是最后一个参数带有*，希望大家注意一下。大家看到这里相信对Route类的GetRouteData方法有个大致的了解了吧。
