HttpModule 破坏了 WebResource.axd

Question

我编写了一个 HttpModule，它进行了一些简单的内容重写。它工作正常，但是它有一个令人讨厌的副作用，即 WebResource.axd 的输出为零字节。我在网上看到了一些对此已知问题的参考，但没有使用像我这样的过滤器。

我在这里做的事情（或忽略）是否会导致 WebResource.axd 中断？我在 IIS 7.5 上使用 ASP.NET 4.0。

Imports System.Text
Imports System.Text.RegularExpressions
Imports System.IO
Imports System.Web

Namespace HttpModules

  Public Class ResponseRewritingModule
    Implements IHttpModule

    Public Sub Init(ByVal app As HttpApplication) Implements IHttpModule.Init
      AddHandler app.ReleaseRequestState, AddressOf Me.OnReleaseRequestState
    End Sub

    Public Sub Dispose() Implements IHttpModule.Dispose
    End Sub

    Public Sub OnReleaseRequestState(ByVal s As Object, ByVal e As EventArgs)
      Dim app As HttpApplication = CType(s, HttpApplication)
      If (app.Request.Url.ToString().Contains(".aspx")) Then
        app.Response.Filter = New ImageUrlResponseFilter(app.Response.Filter)
      End If
    End Sub

  End Class

  Public Class ImageUrlResponseFilter
    Inherits MemoryStream

    Private responseStream As Stream
    Private matchpattern As String = "src=""/Images/"
    Private matchpattern2 As String = "url\(/Images"
    Private matchpattern3 As String = "src = ""/Images/"
    Private matchpattern4 As String = "src=""http://www.mydomain.com/Images/"
    Private replacementstring As String = "src=""http://images.mydomain.com/Images/"
    Private replacementstring2 As String = "url(http://images.mydomain.com/Images"

    Public Sub New(inputStream As Stream)
      responseStream = inputStream
    End Sub

    Public Overrides Sub Write(buffer As Byte(), offset As Integer, count As Integer)

      Dim strBuffer As String = System.Text.UTF8Encoding.UTF8.GetString(buffer)

      If (Not HttpContext.Current.Request.IsSecureConnection) Then
        strBuffer = Regex.Replace(strBuffer, matchpattern, replacementstring, RegexOptions.Compiled Or RegexOptions.IgnoreCase)
        strBuffer = Regex.Replace(strBuffer, matchpattern2, replacementstring2, RegexOptions.Compiled Or RegexOptions.IgnoreCase)
        strBuffer = Regex.Replace(strBuffer, matchpattern3, replacementstring, RegexOptions.Compiled Or RegexOptions.IgnoreCase)
        strBuffer = Regex.Replace(strBuffer, matchpattern4, replacementstring, RegexOptions.Compiled Or RegexOptions.IgnoreCase)
        responseStream.Write(UTF8Encoding.UTF8.GetBytes(strBuffer), offset, UTF8Encoding.UTF8.GetByteCount(strBuffer))
      Else
        ' Do nothing for SSL connections
        responseStream.Write(buffer, offset, count)
      End If

    End Sub

  End Class

End Namespace

更新： Daniel Richardson 似乎已经发现了根本原因，并在这里提供了解决方案：http://daniel-richardson.blogspot.com/2008/11/how-to-apply-filter-to-content-returned.html

微软显然已经知道这个问题很多年了并且不会修复它：http://connect.microsoft.com/VisualStudio/feedback/details/105150/webresource-axd-output-always-truncated-when-used-with-a-response-filter