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This approach requires IIS 7, and will also run in design mode in Visual Studio 2008. If you don't have this technology, Scott Gu details other options in his blog (see the link above).

So, how's it done?
Several techniques are melded together.
1 - We use the URL Rewriting code from www.urlrewriter.net
2 - There are issues with postbacks on forms that use this technique. In order to solve that we take advantage of the new ASP.NET 2.0 Control Adapter extensibility architecture to customize the rendering of the <form> control, and override its "action" attribute value with a value you provide. This solves the problem neatly.

URL Rewriting using www.urlrewriter.net

UrlRewriter.NET is an open-source, light-weight, highly configurable URL rewriting component for ASP.NET 1.1 and 2.0. UrlRewriter.NET provides similar IIS Rewrite capabilities that the Apache web server provides with mod_rewrite and .htaccess. You don’t need to install an ISAPI Rewrite filter to use the component. Best of all, UrlRewriter.NET is free and licensed with a very permissive MIT-style licence.

To use, download and unpack the project, place the dll in your projects bin directory and set a reference to it.
Make the following changes to your web.config file

<?xml version="1.0" encoding="UTF-8"?>


<configuration>


  <configSections>
    <section name="rewriter" 
             requirePermission="false" 
             type="Intelligencia.UrlRewriter.Configuration.RewriterConfigurationSectionHandler, Intelligencia.UrlRewriter" />
  </configSections>
  
  <system.web>
      
    <httpModules>
      <add name="UrlRewriter" type="Intelligencia.UrlRewriter.RewriterHttpModule, Intelligencia.UrlRewriter" />
    </httpModules>
    
  </system.web>


  <system.webServer>


    <modules runAllManagedModulesForAllRequests="true">
      <add name="UrlRewriter" type="Intelligencia.UrlRewriter.RewriterHttpModule" />
    </modules>


    <validation validateIntegratedModeConfiguration="false" />


  </system.webServer>


  <rewriter>
    <rewrite url="~/products/(.+)" to="~/products.aspx?category=$1" />
  </rewriter>
  
</configuration>

Note the "runAllManagedModulesForAllRequests" attribute that is set to true on the <modules> section within <system.webServer>. This will ensure that the UrlRewriter.Net module from Intelligencia, which was written before IIS7 shipped, will be called and have a chance to re-write all URL requests to the server (including for folders). What is really cool about the above web.config file is that:

1) It will work on any IIS 7.0 machine. You don't need an administrator to enable anything on the remote host. It will also work in medium trust shared hosting scenarios.

2) Because we've configured the UrlRewriter in both the <httpModules> and IIS7 <modules> section, we can use the same URL Rewriting rules for both the built-in VS web-server (aka Cassini) as well as on IIS7. Both fully support extension-less URLRewriting. This makes testing and development really easy.

To test, write a default.aspx page like this

 


<html xmlns="<a href="http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</a>">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    default page<br />
    <a href="articles.aspx?art=links" mce_href="articles.aspx?art=links">links (using the regular style of link)<br />
    <a href="articles/links" mce_href="articles/links">links (using the 'rewritten' link)</a>
    <br />
    This image is show to prove that we won't lose the reference to it<br>
    <asp:Image ID="imgGabby" runat="server" ImageUrl="~/images/gabby.jpg" />
    </div>
    </form>
</body>
</html>

and an articles.aspx page like this

 


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "<a href="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd</a>">


<html xmlns="<a href="http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</a>">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <a href="/Default.aspx" mce_href="/Default.aspx">Home<br />
        articles <br />
        article name: <br ID="lblArticleNumber" runat="server" />
        <br ID="btnPostBack" runat="server" Text="Post Back" />
        </asp:Label ID="lblTime" runat="server">
        <br />
        This image is show to prove that we won't lose the reference to it<br>
        <asp:Image ID="imgGabby" runat="server" ImageUrl="~/images/gabby.jpg" />


    </div>
    </form>
</body>
</html>

I added code behind the articles page like to demonstrate what's going on. In the Page_Load we get the 'art' value from the querystring and display it on the page. There is also a label named 'lblTime' that we populate on the postback event of btnPostBack, to demonstrate the issue that occurs on post backs. We'll solve that in the next section. For now, get this working. Note that we also include an image on this page, to demonstrate that we are not loosing the references in an of this manuvering. The key is to qualify all css and image sources to the root of the application: "style.css" becomes "/style.css", and anything referenced in an asp control just needs the '~' in front of it, like this: <asp:Image ID="imgGabby" runat="server" ImageUrl="~/images/gabby.jpg" />

 


    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Request("art") > "" Then
            Me.lblArticleNumber.Text = Request("art")
        End If
    End Sub


    Protected Sub btnPostBack_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnPostBack.Click
        Me.lblTime.text = Now
    End Sub

Next, let's look at the more complicated postback issue. Without this code, if you send your page to http://mysite.com/articles/links, if for any reason you do a postback on that page it will show up the second time as http://mysite.com/articles.aspx?art=links. In order to fix this, add a new 'browser' file (WEBSITE > ADD NEW ITEM, choose the 'browser file' icon). This should show up in the App_browsers folder. Here is the code:

 


<browsers>
 <browser refID="Default">
  <controlAdapters>
   <adapter controlType="System.Web.UI.HtmlControls.HtmlForm"
      adapterType="FormRewriterControlAdapter" />
  </controlAdapters>
 </browser>
</browsers>

Now create a new class called FormRewriter.vb (this should appear in the App_Code folder). Here is the code:

 


Imports Microsoft.VisualBasic


Public Class FormRewriterControlAdapter
    Inherits System.Web.UI.Adapters.ControlAdapter


    Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
        MyBase.Render(New RewriteFormHtmlTextWriter(writer))
    End Sub


End Class


Public Class RewriteFormHtmlTextWriter
    Inherits HtmlTextWriter


    Sub New(ByVal writer As HtmlTextWriter)
        MyBase.New(writer)
        Me.InnerWriter = writer.InnerWriter
    End Sub


    Sub New(ByVal writer As System.IO.TextWriter)
        MyBase.New(writer)
        MyBase.InnerWriter = writer
    End Sub


    Public Overrides Sub WriteAttribute(ByVal name As String, ByVal value As String, ByVal fEncode As Boolean)


        ' If the attribute we are writing is the "action" attribute, and we are not on a sub-control, 
        ' then replace the value to write with the raw URL of the request - which ensures that we'll
        ' preserve the PathInfo value on postback scenarios


        If (name = "action") Then


            Dim Context As HttpContext
            Context = HttpContext.Current


            If Context.Items("ActionAlreadyWritten") Is Nothing Then


                ' Because we are using the UrlRewriting.net HttpModule, we will use the 
                ' Request.RawUrl property within ASP.NET to retrieve the origional URL
                ' before it was re-written.  You'll want to change the line of code below
                ' if you use a different URL rewriting implementation.


                value = Context.Request.RawUrl


                ' Indicate that we've already rewritten the <form>'s action attribute to prevent
                ' us from rewriting a sub-control under the <form> control


                Context.Items("ActionAlreadyWritten") = True


            End If


        End If


        MyBase.WriteAttribute(name, value, fEncode)


    End Sub


End Class

Exactly how this works is beyond the scope of this article, but it does and this should be all you need.

Posted Dec 06 2008, 03:55 PM by Steve Gray

adovbs.inc

I've avoided blogging this because I always figured that it would just... go away, but I always seem to need something from here.

Here's the standard adovbs.inc file.

The whole thing needs to be wrapped in <%... %> if you really want to use it right... I usually just want a value

'--------------------------------------------------------------------
' Microsoft ADO
'
' (c) 1996-1998 Microsoft Corporation.  All Rights Reserved.
'
'
'
' ADO constants include file for VBScript
'
'--------------------------------------------------------------------


'---- CursorTypeEnum Values ----
Const adOpenForwardOnly = 0
Const adOpenKeyset = 1
Const adOpenDynamic = 2
Const adOpenStatic = 3


'---- CursorOptionEnum Values ----
Const adHoldRecords = &H00000100
Const adMovePrevious = &H00000200
Const adAddNew = &H01000400
Const adDelete = &H01000800
Const adUpdate = &H01008000
Const adBookmark = &H00002000
Const adApproxPosition = &H00004000
Const adUpdateBatch = &H00010000
Const adResync = &H00020000
Const adNotify = &H00040000
Const adFind = &H00080000
Const adSeek = &H00400000
Const adIndex = &H00800000


'---- LockTypeEnum Values ----
Const adLockReadOnly = 1
Const adLockPessimistic = 2
Const adLockOptimistic = 3
Const adLockBatchOptimistic = 4


'---- ExecuteOptionEnum Values ----
Const adRunAsync = &H00000010
Const adAsyncExecute = &H00000010
Const adAsyncFetch = &H00000020
Const adAsyncFetchNonBlocking = &H00000040
Const adExecuteNoRecords = &H00000080


'---- ConnectOptionEnum Values ----
Const adAsyncConnect = &H00000010


'---- ObjectStateEnum Values ----
Const adStateClosed = &H00000000
Const adStateOpen = &H00000001
Const adStateConnecting = &H00000002
Const adStateExecuting = &H00000004
Const adStateFetching = &H00000008


'---- CursorLocationEnum Values ----
Const adUseServer = 2
Const adUseClient = 3


'---- DataTypeEnum Values ----
Const adEmpty = 0
Const adTinyInt = 16
Const adSmallInt = 2
Const adInteger = 3
Const adBigInt = 20
Const adUnsignedTinyInt = 17
Const adUnsignedSmallInt = 18
Const adUnsignedInt = 19
Const adUnsignedBigInt = 21
Const adSingle = 4
Const adDouble = 5
Const adCurrency = 6
Const adDecimal = 14
Const adNumeric = 131
Const adBoolean = 11
Const adError = 10
Const adUserDefined = 132
Const adVariant = 12
Const adIDispatch = 9
Const adIUnknown = 13
Const adGUID = 72
Const adDate = 7
Const adDBDate = 133
Const adDBTime = 134
Const adDBTimeStamp = 135
Const adBSTR = 8
Const adChar = 129
Const adVarChar = 200
Const adLongVarChar = 201
Const adWChar = 130
Const adVarWChar = 202
Const adLongVarWChar = 203
Const adBinary = 128
Const adVarBinary = 204
Const adLongVarBinary = 205
Const adChapter = 136
Const adFileTime = 64
Const adDBFileTime = 137
Const adPropVariant = 138
Const adVarNumeric = 139


'---- FieldAttributeEnum Values ----
Const adFldMayDefer = &H00000002
Const adFldUpdatable = &H00000004
Const adFldUnknownUpdatable = &H00000008
Const adFldFixed = &H00000010
Const adFldIsNullable = &H00000020
Const adFldMayBeNull = &H00000040
Const adFldLong = &H00000080
Const adFldRowID = &H00000100
Const adFldRowVersion = &H00000200
Const adFldCacheDeferred = &H00001000
Const adFldKeyColumn = &H00008000


'---- EditModeEnum Values ----
Const adEditNone = &H0000
Const adEditInProgress = &H0001
Const adEditAdd = &H0002
Const adEditDelete = &H0004


'---- RecordStatusEnum Values ----
Const adRecOK = &H0000000
Const adRecNew = &H0000001
Const adRecModified = &H0000002
Const adRecDeleted = &H0000004
Const adRecUnmodified = &H0000008
Const adRecInvalid = &H0000010
Const adRecMultipleChanges = &H0000040
Const adRecPendingChanges = &H0000080
Const adRecCanceled = &H0000100
Const adRecCantRelease = &H0000400
Const adRecConcurrencyViolation = &H0000800
Const adRecIntegrityViolation = &H0001000
Const adRecMaxChangesExceeded = &H0002000
Const adRecObjectOpen = &H0004000
Const adRecOutOfMemory = &H0008000
Const adRecPermissionDenied = &H0010000
Const adRecSchemaViolation = &H0020000
Const adRecDBDeleted = &H0040000


'---- GetRowsOptionEnum Values ----
Const adGetRowsRest = -1


'---- PositionEnum Values ----
Const adPosUnknown = -1
Const adPosBOF = -2
Const adPosEOF = -3


'---- enum Values ----
Const adBookmarkCurrent = 0
Const adBookmarkFirst = 1
Const adBookmarkLast = 2


'---- MarshalOptionsEnum Values ----
Const adMarshalAll = 0
Const adMarshalModifiedOnly = 1


'---- AffectEnum Values ----
Const adAffectCurrent = 1
Const adAffectGroup = 2
Const adAffectAll = 3
Const adAffectAllChapters = 4


'---- ResyncEnum Values ----
Const adResyncUnderlyingValues = 1
Const adResyncAllValues = 2


'---- CompareEnum Values ----
Const adCompareLessThan = 0
Const adCompareEqual = 1
Const adCompareGreaterThan = 2
Const adCompareNotEqual = 3
Const adCompareNotComparable = 4


'---- FilterGroupEnum Values ----
Const adFilterNone = 0
Const adFilterPendingRecords = 1
Const adFilterAffectedRecords = 2
Const adFilterFetchedRecords = 3
Const adFilterPredicate = 4
Const adFilterConflictingRecords = 5


'---- SearchDirectionEnum Values ----
Const adSearchForward = 1
Const adSearchBackward = -1


'---- PersistFormatEnum Values ----
Const adPersistADTG = 0
Const adPersistXML = 1


'---- StringFormatEnum Values ----
Const adStringXML = 0
Const adStringHTML = 1
Const adClipString = 2


'---- ConnectPromptEnum Values ----
Const adPromptAlways = 1
Const adPromptComplete = 2
Const adPromptCompleteRequired = 3
Const adPromptNever = 4


'---- ConnectModeEnum Values ----
Const adModeUnknown = 0
Const adModeRead = 1
Const adModeWrite = 2
Const adModeReadWrite = 3
Const adModeShareDenyRead = 4
Const adModeShareDenyWrite = 8
Const adModeShareExclusive = &Hc
Const adModeShareDenyNone = &H10


'---- IsolationLevelEnum Values ----
Const adXactUnspecified = &Hffffffff
Const adXactChaos = &H00000010
Const adXactReadUncommitted = &H00000100
Const adXactBrowse = &H00000100
Const adXactCursorStability = &H00001000
Const adXactReadCommitted = &H00001000
Const adXactRepeatableRead = &H00010000
Const adXactSerializable = &H00100000
Const adXactIsolated = &H00100000


'---- XactAttributeEnum Values ----
Const adXactCommitRetaining = &H00020000
Const adXactAbortRetaining = &H00040000


'---- PropertyAttributesEnum Values ----
Const adPropNotSupported = &H0000
Const adPropRequired = &H0001
Const adPropOptional = &H0002
Const adPropRead = &H0200
Const adPropWrite = &H0400


'---- ErrorValueEnum Values ----
Const adErrInvalidArgument = &Hbb9
Const adErrNoCurrentRecord = &Hbcd
Const adErrIllegalOperation = &Hc93
Const adErrInTransaction = &Hcae
Const adErrFeatureNotAvailable = &Hcb3
Const adErrItemNotFound = &Hcc1
Const adErrObjectInCollection = &Hd27
Const adErrObjectNotSet = &Hd5c
Const adErrDataConversion = &Hd5d
Const adErrObjectClosed = &He78
Const adErrObjectOpen = &He79
Const adErrProviderNotFound = &He7a
Const adErrBoundToCommand = &He7b
Const adErrInvalidParamInfo = &He7c
Const adErrInvalidConnection = &He7d
Const adErrNotReentrant = &He7e
Const adErrStillExecuting = &He7f
Const adErrOperationCancelled = &He80
Const adErrStillConnecting = &He81
Const adErrNotExecuting = &He83
Const adErrUnsafeOperation = &He84


'---- ParameterAttributesEnum Values ----
Const adParamSigned = &H0010
Const adParamNullable = &H0040
Const adParamLong = &H0080


'---- ParameterDirectionEnum Values ----
Const adParamUnknown = &H0000
Const adParamInput = &H0001
Const adParamOutput = &H0002
Const adParamInputOutput = &H0003
Const adParamReturnValue = &H0004


'---- CommandTypeEnum Values ----
Const adCmdUnknown = &H0008
Const adCmdText = &H0001
Const adCmdTable = &H0002
Const adCmdStoredProc = &H0004
Const adCmdFile = &H0100
Const adCmdTableDirect = &H0200


'---- EventStatusEnum Values ----
Const adStatusOK = &H0000001
Const adStatusErrorsOccurred = &H0000002
Const adStatusCantDeny = &H0000003
Const adStatusCancel = &H0000004
Const adStatusUnwantedEvent = &H0000005


'---- EventReasonEnum Values ----
Const adRsnAddNew = 1
Const adRsnDelete = 2
Const adRsnUpdate = 3
Const adRsnUndoUpdate = 4
Const adRsnUndoAddNew = 5
Const adRsnUndoDelete = 6
Const adRsnRequery = 7
Const adRsnResynch = 8
Const adRsnClose = 9
Const adRsnMove = 10
Const adRsnFirstChange = 11
Const adRsnMoveFirst = 12
Const adRsnMoveNext = 13
Const adRsnMovePrevious = 14
Const adRsnMoveLast = 15


'---- SchemaEnum Values ----
Const adSchemaProviderSpecific = -1
Const adSchemaAsserts = 0
Const adSchemaCatalogs = 1
Const adSchemaCharacterSets = 2
Const adSchemaCollations = 3
Const adSchemaColumns = 4
Const adSchemaCheckConstraints = 5
Const adSchemaConstraintColumnUsage = 6
Const adSchemaConstraintTableUsage = 7
Const adSchemaKeyColumnUsage = 8
Const adSchemaReferentialConstraints = 9
Const adSchemaTableConstraints = 10
Const adSchemaColumnsDomainUsage = 11
Const adSchemaIndexes = 12
Const adSchemaColumnPrivileges = 13
Const adSchemaTablePrivileges = 14
Const adSchemaUsagePrivileges = 15
Const adSchemaProcedures = 16
Const adSchemaSchemata = 17
Const adSchemaSQLLanguages = 18
Const adSchemaStatistics = 19
Const adSchemaTables = 20
Const adSchemaTranslations = 21
Const adSchemaProviderTypes = 22
Const adSchemaViews = 23
Const adSchemaViewColumnUsage = 24
Const adSchemaViewTableUsage = 25
Const adSchemaProcedureParameters = 26
Const adSchemaForeignKeys = 27
Const adSchemaPrimaryKeys = 28
Const adSchemaProcedureColumns = 29
Const adSchemaDBInfoKeywords = 30
Const adSchemaDBInfoLiterals = 31
Const adSchemaCubes = 32
Const adSchemaDimensions = 33
Const adSchemaHierarchies = 34
Const adSchemaLevels = 35
Const adSchemaMeasures = 36
Const adSchemaProperties = 37
Const adSchemaMembers = 38


'---- SeekEnum Values ----
Const adSeekFirstEQ = &H1
Const adSeekLastEQ = &H2
Const adSeekAfterEQ = &H4
Const adSeekAfter = &H8
Const adSeekBeforeEQ = &H10
Const adSeekBefore = &H20


'---- ADCPROP_UPDATECRITERIA_ENUM Values ----
Const adCriteriaKey = 0
Const adCriteriaAllCols = 1
Const adCriteriaUpdCols = 2
Const adCriteriaTimeStamp = 3


'---- ADCPROP_ASYNCTHREADPRIORITY_ENUM Values ----
Const adPriorityLowest = 1
Const adPriorityBelowNormal = 2
Const adPriorityNormal = 3
Const adPriorityAboveNormal = 4
Const adPriorityHighest = 5


'---- CEResyncEnum Values ----
Const adResyncNone = 0
Const adResyncAutoIncrement = 1
Const adResyncConflicts = 2
Const adResyncUpdates = 4
Const adResyncInserts = 8
Const adResyncAll = 15


'---- ADCPROP_AUTORECALC_ENUM Values ----
Const adRecalcUpFront = 0
Const adRecalcAlways = 1

Posted Dec 05 2008, 12:40 PM by Steve Gray

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