我正在使用 ASP.NET 4.0 路由并正在从数据库中读取路由信息并添加如下路由。简而言之，我的自定义对象“RouteLookup”包含路由信息，包括它可能会或可能不会重定向到的另一个 RouteLookup 的 ID。这是数据库中两个 RouteLookup 条目的示例：
RouteLookupID RouteName RelativePath RequestHandler RouteHandler IsSecure RedirectedToRoute
13 PrivacyRoute about/privacy privacy.aspx NULL 0 0
14 PrivacyRoute1 privacy privacy.aspx NULL 0 13
RouteLookupID 14 是需要永久重定向到 RouteLookupID 13 的旧路由。我遇到的问题是当我从浏览器请求“ http://mydomain.com/privacy ”并观看 Fiddler 结果时，它实际上重定向TWICE 并添加一个“count=0”作为查询字符串参数！我没有这个参数来自哪里的想法，因为我没有明确添加它的进程、httphandler 等。
这里到底发生了什么？非常感谢任何想法，其余相关代码如下。
我有一个类 BaseRoute，它继承自 Route，因此我可以将我的自定义 RouteLookup 对象与它一起传递，以便在我命名为 BaseRouteHandler 的自定义 RouteHandler 中进行检查。
Public Class PageRouter
Private Shared db As New QADBDataContext
''''''' Is called from Global Application_Start
Public Shared Sub MapRoutes(routeColl As RouteCollection)
Dim routeLookups As IEnumerable(Of RouteLookup) = From rt In db.RouteLookups Select rt
For Each rtLookUp As RouteLookup In routeLookups
Dim parameterizedURL As String = BuildParameterizedVirtualPath(rtLookUp)
' Determine handler and route values
If rtLookUp.RouteHandler Is Nothing Then
RouteTable.Routes.Add(rtLookUp.RouteName, New BaseRoute(parameterizedURL, New BaseRouteHandler(), rtLookUp))
Else
RouteTable.Routes.Add(rtLookUp.RouteName, New BaseRoute(parameterizedURL, Activator.CreateInstance(Type.GetType("QA." + rtLookUp.RouteHandler)), rtLookUp))
End If
Next
End Sub
Protected Shared Function BuildParameterizedVirtualPath(rtLookUp As RouteLookup) As String
Dim parameterizedURL As String = rtLookUp.RelativePath
For Each param As RouteParameter In rtLookUp.RouteParameters
parameterizedURL &= "/{" + param.Name + "}"
Next
Return parameterizedURL
End Function
Public Shared Sub RedirectToRoutePermanent(rtData As RouteData)
Dim route As BaseRoute = DirectCast(rtData.Route, BaseRoute)
Dim rtLookup As RouteLookup = route.RouteLookup
Dim newRtLookupID As Integer = rtLookup.RedirectedToRoute
Dim newRtLookup As RouteLookup = (From rt In db.RouteLookups Where rt.RouteLookupID = newRtLookupID).SingleOrDefault
HttpContext.Current.Response.RedirectToRoutePermanent(newRtLookup.RouteName, rtData.Values.Values)
End Sub
End Class
自定义路由类：
Public Class BaseRoute
Inherits Route
Private _routeLookup As RouteLookup = Nothing
Public Sub New(url As String, routeHandler As IRouteHandler, routeLookup As RouteLookup)
MyBase.New(url, routeHandler)
_routeLookup = routeLookup
End Sub
Public ReadOnly Property RouteLookup As RouteLookup
Get
Return _routeLookup
End Get
End Property
End Class
自定义路由处理程序：
Public Class BaseRouteHandler
Implements IRouteHandler
Protected _baseRoute As BaseRoute = Nothing
Protected _rtLookup As RouteLookup = Nothing
Protected Overridable Sub InitializeContext(ByVal requestContext As System.Web.Routing.RequestContext)
_baseRoute = DirectCast(requestContext.RouteData.Route, BaseRoute)
_rtLookup = _baseRoute.RouteLookup
End Sub
Public Function GetHttpHandler(ByVal requestContext As System.Web.Routing.RequestContext) _
As System.Web.IHttpHandler Implements System.Web.Routing.IRouteHandler.GetHttpHandler
InitializeContext(requestContext)
EnforceURLStandard(requestContext)
PerformRedirectIfNeeded(requestContext)
Return GetPageHandler(requestContext)
End Function
Protected Overridable Sub PerformRedirectIfNeeded(ByVal requestContext As System.Web.Routing.RequestContext)
If _rtLookup.RedirectedToRoute > 0 Then
PageRouter.RedirectToRoutePermanent(requestContext.RouteData)
End If
End Sub
Protected Sub EnforceURLStandard(ByVal requestContext As System.Web.Routing.RequestContext)
' Test for:
' * Proper protocol
' * www. exists
' * must be all lowercase
Dim scheme As String = HttpContext.Current.Request.Url.GetComponents(UriComponents.Scheme, UriFormat.UriEscaped)
Dim rightSide As String = HttpContext.Current.Request.Url.GetComponents(UriComponents.HostAndPort Or UriComponents.PathAndQuery, UriFormat.UriEscaped)
Dim newURL As String = Nothing
If Not rightSide.ToLower().StartsWith("www.") AndAlso Not rightSide.ToLower().StartsWith("localhost") _
AndAlso Not rightSide.ToLower().StartsWith("uat") AndAlso Not rightSide.ToLower().StartsWith("ux") Then
newURL = scheme & "://www." & rightSide
End If
If _rtLookup.IsSecure <> requestContext.HttpContext.Request.IsSecureConnection Then
Dim newScheme As String = If(_rtLookup.IsSecure, "https", "http")
newURL = newScheme & rightSide
End If
Dim pattern As String = "[A-Z]"
If Not String.IsNullOrWhiteSpace(newURL) Then
If Regex.IsMatch(newURL, pattern) Then
newURL = newURL.ToLower()
End If
Else
If Regex.IsMatch(HttpContext.Current.Request.Url.ToString(), pattern) Then
newURL = HttpContext.Current.Request.Url.ToString().ToLower()
End If
End If
If Not newURL Is Nothing Then
HttpContext.Current.Response.RedirectPermanent(newURL, True)
End If
End Sub
Protected Overridable Function GetPageHandler(ByVal requestContext As System.Web.Routing.RequestContext) As System.Web.IHttpHandler
Return TryCast(BuildManager.CreateInstanceFromVirtualPath("/" & _rtLookup.RequestHandler, GetType(Page)), Page)
End Function
End Class