.NET FOLLOWER

    After migration of a SharePoint 2007 application to SharePoint 2010 we encountered an unhandled exception occurring arbitrarily when a list item is opening for editing. The exception looks as follows:

Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: s

Source Error: 
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. 

Stack Trace: 

[ArgumentNullException: Value cannot be null. Parameter name: s]
   System.IO.StringReader..ctor(String s) +10151478
   Microsoft.SharePoint.Publishing.Internal.WorkflowUtilities.FlattenXmlToHashtable(String strXml) +117
   Microsoft.SharePoint.Publishing.Internal.WorkflowUtilities.DoesWorkflowCancelWhenItemEdited(String associationXml) +12
   Microsoft.SharePoint.Publishing.WebControls.ConsoleDataSource.EnsurePageNotInLockingWorkflowIfInEditMode() +207
   Microsoft.SharePoint.Publishing.WebControls.ConsoleDataSource.LoadDataSource() +199
   Microsoft.SharePoint.Publishing.WebControls.ConsoleDataSource.OnLoad(EventArgs e) +98
   Microsoft.SharePoint.Publishing.WebControls.XmlConsoleDataSource.OnLoad(EventArgs e) +201
   Microsoft.SharePoint.Publishing.WebControls.PublishingSiteActionsMenuCustomizer.OnLoad(EventArgs e) +186
   System.Web.UI.Control.LoadRecursive() +66
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2428

Having analyzed the stack trace we found out that the issue is, evidently, caused by workflow infrastructure. In the SharePoint application we have both handmade custom workflows and the ones that were made in SharePoint Designer (so called SPD Workflows). It’s interesting that the exception was rising for both workflow types. After some investigation using .Net Reflector, we discovered that the AssociationData xml-element is a cause of our troubles. The AssociationData is an element of the Workflow Definition Schema and specifies any custom data to pass to the workflow association form. Additionally, we use the association data when starting workflow on list items through the code. The workflow infrastructure, in SharePoint 2010, supposes that the AssociationData element is a valid xml string. So, if it’s empty or contains any data without xml-tags, the exception is thrown as opposite to SP 2007.

The solution consists of two steps. Firstly, for every Workflow Definition in your project you need to set <AssociationData> so that it contains a valid xml. Regardless of whether association data is actually used or not, <AssociationData> has to be presented in Workflow Definition and contain at least a fake valid xml. For example, I set dummy <Data />. In case you deploy a custom workflow through a SharePoint Feature, the Workflow Definition is usually located in Elements.xml file. If <AssociationData> element doesn’t exist within <Workflow> tag, add it at the same level as <MetaData>. The resultant workflow definition should look like:

<?xml version="1.0" encoding="utf-8" ?> 
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <Workflow ...>
    ...
    <AssociationData>
      <Data />
    </AssociationData>
    <MetaData>
      ...
    </MetaData>
    ...
  </Workflow>
</Elements>

The described first step of the solution affects only new applications created after the alterations have been applied to Workflow Definitions. Even if a SharePoint Feature containing a custom workflow is reactivated, changes are only applied to workflow instances that start after the workflow association is modified. But for live applications created before or migrated from previous version of SharePoint (like in my case), the first step is useless. Additionally, you may have the SPD workflow which doesn’t include usual Workflow Definition at all. So, the second step is a necessary and sufficient part of the solution.

The second step is get all SPWorkflowAssociation objects and adjust their AssociationData properties programmatically. I’ve developed a few methods allowing to achieve this goal. See the listing below:

using System;
using System.Xml;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Workflow;

...

/// <summary>
/// Adjusts AssociationData properties of all Workflow Associations related to the passed Web, its child Lists and Content Types
/// </summary>
public static void AdjustAllWorkflowAssociations(SPWeb web)
{
    AdjustWebWorkflowAssociation(web);

    for (int i = 0; i < web.ContentTypes.Count; i ++)
        AdjustContentTypeWorkflowAssociation(web.ContentTypes[i]);

    for (int i = 0; i < web.Lists.Count; i ++)
    {
        AdjustListWorkflowAssociation(web.Lists[i]);
        for (int j = 0; j < web.Lists[i].ContentTypes.Count; j ++)
            AdjustContentTypeWorkflowAssociation(web.Lists[i].ContentTypes[j]);
    }
}

/// <summary>
/// Adjusts AssociationData properties of all Workflow Associations related to the passed List
/// </summary>
public static void AdjustListWorkflowAssociation(SPList list)
{
    AdjustAssociationData(list.WorkflowAssociations);
}

/// <summary>
/// Adjusts AssociationData properties of all Workflow Associations related to the passed Web
/// </summary>
public static void AdjustWebWorkflowAssociation(SPWeb web)
{
    AdjustAssociationData(web.WorkflowAssociations);
}

/// <summary>
/// Adjusts AssociationData properties of all Workflow Associations related to the passed Content Type
/// </summary>
public static void AdjustContentTypeWorkflowAssociation(SPContentType contentType)
{
    AdjustAssociationData(contentType.WorkflowAssociations);
}

/// <summary>
/// Adjusts AssociationData properties of all Workflow Associations in the passed collection
/// </summary>
public static void AdjustAssociationData(SPWorkflowAssociationCollection collection)
{
    for (int i = 0; i < collection.Count; i ++)
        AdjustAssociationData(collection[i], collection);
}

/// <summary>
/// Sets AssociationData property if it's not valid
/// </summary>
public static void AdjustAssociationData(SPWorkflowAssociation workflowAssociation, SPWorkflowAssociationCollection collection)
{
    if (!IsValidXml(workflowAssociation.AssociationData))
    {
        string newValue = string.IsNullOrEmpty(workflowAssociation.AssociationData)
                                ? "<Data />"
                                : string.Format("<Data>{0}</Data>", workflowAssociation.AssociationData);
        workflowAssociation.AssociationData = newValue;
        collection.Update(workflowAssociation);
    }
}

/// <summary>
/// Checks if the passed string is a valid xml
/// </summary>
public static bool IsValidXml(string str)
{
    if (!string.IsNullOrEmpty(str))
    {
        try
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.LoadXml(str);
            return true;
        }
        catch {}
    }
    return false;
}

The basic method in the set is AdjustAssociationData, which examines AssociationData property of a passed SPWorkflowAssociation object and then applies a valid xml-value to the property if it’s necessary. As we know, workflows can be associated with webs, lists or content types. The AdjustWebWorkflowAssociation, AdjustListWorkflowAssociation and AdjustContentTypeWorkflowAssociation methods adjust AssociationData of a passed SPWeb, SPList or SPContentType object respectively. Finally, the AdjustAllWorkflowAssociations tries to adjust all available workflow associations that can be reached through a passed SPWeb instance.

Note that I everywhere used the for-statement instead of foreach, because otherwise the exception “Collection was modified; enumeration operation may not execute” will be thrown.

Below is the piece of code from the simple console application, which I used against our problem SharePoint application:

static void Main(string[] args)
{
    try
    {
        AppArguments arguments = new AppArguments(args);

        if(string.IsNullOrEmpty(arguments.Url))
        {
            Console.WriteLine("Invalid application URL!");
            return;
        }

        using (SPSite spSite = new SPSite(arguments.Url))
            using (SPWeb spWeb = spSite.OpenWeb())
                AdjustAllWorkflowAssociations(spWeb);

    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}

Where the AppArguments is a class derived from InputArguments. InputArguments is described here – Simple Command Line Arguments Parser.

public class AppArguments : InputArguments
{
    public string Url
    {
        get { return GetValue("url"); }
    }

    public AppArguments(string[] args) : base(args)
    {
    }
}

As for our SharePoint application, it has only workflows associated with lists. So, after executing of the console app described above, the exception in question is gone. I hope it’ll help somebody as well.

The full version of the console app you can download here (Visual Studio 2010 solution). To execute it use the command line with parameters as follows:

AdjustAssociationData.exe -url "http://yourservername/yourapppath"

    Our production SharePoint Farm and customer users are deployed in one domain, let’s call it Root, while the development and quality control farms are in a child domain, let’s name it Child.Root. The Child.Root domain trust to the parent Root domain, while the Root domain knows nothing about the Child.Root. So, we have a one way trust domains configuration where the Child.Root trusts Root, but not vice versa. Under such conditions we have faced the issue with SharePoint Search when an user from the trusted parent Root domain gets zero results, executing a search query on the Child.Root.

The solution was borrowed from the Microsoft Knowledge Base Article – Unable to Perform a query on a One-Way trust Domains Scenario when an User from the trusted domain performs the query and the SSA Application Pool account is from the Trustee Domain. The topology described in the KB article presumes that domains with a one way trust relationship are in two separate forests. Despite the fact that in our case both domains are in one forest, the solution works great, though.

So, you need to follow these steps:

1. Launch SharePoint 2010 Management Shell (click on Start, then All Programs -> Microsoft SharePoint 2010 Products -> SharePoint 2010 Management Shell);
2. Type $searchapp = Get-SPEnterpriseSearchServiceApplication and press Enter;
3. Type $searchapp.SetProperty(“ForceClaimACLs”,1) and press Enter. Don’t wait for any confirmation, you won’t see it;
   
4. Restart a full crawl through Central Administration (click on Start, then All Programs -> Microsoft SharePoint 2010 Products -> SharePoint 2010 Central Administration, then go to Application Management -> Manage Service Applications -> Search Service Application, then in Crawling section click on Content Sources, open context menu for the Content Source you want to re-crawl, for example, Local SharePoint sites and click Start Full Crawl);
   

After the SetProperty() command has set value of the ForceClaimACLs parameter in the search administration database to 1, ACLs are stored as Claims instead of NT tokens. Note, however, that you needn’t switch other SharePoint applications (different from the Search Service Application) to Claims based authentication. Also, keep in mind that this is a one-way change, so you won’t be able to reverse it back to classic mode.

After the full crawl is performed, users see search results, regardless from which domain they are logged in.

    In our SharePoint applications we actively use writing into Application Event Log. After adding a new Windows 2008 Server R2 machine to our SP 2010 farm, we was getting the exception “System.ComponentModel.Win32Exception: Access is denied” with the description “Cannot open log for source {*}. You may not have write access.” Apparently, the given error is caused by writing to log when it’s called under an ordinary user with limited rights, who, however, can view web pages. I tried to provide Authenticated Users group with Full Control to the [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog] registry key, with no success though.

The workaround is add or modify the magic CustomSD value under the registry key [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application]. So,

1. Open Registry Editor (click Start, then Run, then type regedit and click Ok);
2. Locate the [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application] key in the registry tree;
3. If the CustomSD value doesn’t exist, create it (right click on Application key, then click New -> String Value and set CustomSD name). Then set value data to O:BAG:SYD:(A;;0x3;;;AU) (right click on CustomSD, then click Modify, type the O:BAG:SYD:(A;;0x3;;;AU) and click Ok). The result should look as shown on the picture below:
   
4. If the CustomSD value already exists, append (A;;0x3;;;AU) to the value data (right click on CustomSD, then click Modify, type the (A;;0x3;;;AU) at the end of value data and click Ok). After appending, the resultant value data would be similar to:

   O:BAG:SYD:(D;;0xf0007;;;AN)(D;;0xf0007;;;BG)(A;;0x f0007;;;SY)(A;;0x7;;;BA)(A;;0x7;;;SO)(A;;0x3;;;IU)(A;;0x3;;;SU)(A;;0x3;;;S-1-5-3)(A;;0x3;;;AU)

The CustomSD registry value describes which accounts have the read/write/clear permissions to Application Event Log. The format of the value data corresponds to Security Descriptor Definition Language (SDDL), so (A;;0x3;;;AU) consists of

• A – SDDL_ACCESS_ALLOWED or ACCESS_ALLOWED_ACE_TYPE, one of ACE types;
• 0x3 – ELF_LOGFILE_WRITE (0x2) & ELF_LOGFILE_READ (0x1), the access rights to the EventLog;
• AU – Authenticated Users group;

It looks funny that direct giving permissions for Authenticated Users group haven’t had effect, while the EventLog‘s security is controlled by the CustomSD registry value.

Update: If a web application supports anonymous access, you’d better replace AU in (A;;0x3;;;AU) with WD, where WD is Everyone or a group that includes all users. So, the final version in this case is (A;;0x3;;;WD).

Related posts:

• SharePoint: Simple Event Logger

    As you probably know, in SharePoint 2010 Business Data Connectivity replaced Business Data Catalog of SharePoint 2007. Some changes affects how Business Data Columns are presented in a list’s schema. In SP 2007 a declaration of a Business Data Column in a schema.xml may look like the following:

<Field Type="BusinessData" DisplayName="Product"
Required="FALSE" ID="{bc203358-6113-470f-9b08-f6100cc034f2}"
StaticName="Product" BaseRenderingType="Text" Name="Product"
SystemInstance="ExternalProductDB_Instance" Entity="Products"
BdcField="Name" Profile="" HasActions="False"
RelatedField="Products_ID"
RelatedFieldBDCField="" RelatedFieldWssStaticName="Products_ID"

SecondaryFieldBdcNames="Price:Producer"
SecondaryFieldWssNames="Product_x003a__x0020_Price:Product_x003a__x0020_Producer"
SecondaryFieldsWssStaticNames="Product_x003a__x0020_Price:Product_x003a__x0020_Producer" />

In contrast, in SP 2010 it looks like

<Field Type="BusinessData" DisplayName="Product"
Required="FALSE" ID="{bc203358-6113-470f-9b08-f6100cc034f2}"
StaticName="Product" BaseRenderingType="Text" Name="Product"
SystemInstance="ExternalProductDB_Instance" Entity="Products"
BdcField="Name" Profile="" HasActions="False"
RelatedField="Products_ID"
RelatedFieldBDCField="" RelatedFieldWssStaticName="Products_ID"

SecondaryFieldBdcNames="6%209%20Price%20Producer%204"
SecondaryFieldWssNames="27%2030%20Product%5Fx003a%5F%5Fx0020%5FPrice%20Product%5Fx003a%5F%5Fx0020%5FProducer%206"
SecondaryFieldsWssStaticNames="27%2030%20Product%5Fx003a%5F%5Fx0020%5FPrice%20Product%5Fx003a%5F%5Fx0020%5FProducer%206" />

Undoubtedly, in SP 2010 the secondary fields became practically unreadable. Indeed, the format of secondary fields‘ presentation is revised. Moreover some kind of URL encoding are applied to them. Let’s examine how these secondary fields could look before the URL encoding is applied:

<Field
...
SecondaryFieldBdcNames="6 9 Price Producer 4"
SecondaryFieldWssNames="27 30 Product_x003a__x0020_Price Product_x003a__x0020_Producer 6"
SecondaryFieldsWssStaticNames="27 30 Product_x003a__x0020_Price Product_x003a__x0020_Producer 6" />

Now it’s pretty easy to figure out the new format. Take a look at the SecondaryFieldBdcNames attribute. It contains names of two secondary bdc fields: ‘Price’ and ‘Producer’. 6 is the length of the ‘Price’ name + 1 for a space character right after the name. 9 is the length of the ‘Procuder’ name + 1 for a space character after the name. 4 is the length of the sub-string ‘6 9 ‘ (including spaces), which contains the lengths of the fields’ names. See a picture below:

Note that the SecondaryFieldBdcNames, SecondaryFieldWssNames and SecondaryFieldsWssStaticNames have the same format.

We have a lot of code interacting with Business Data Columns, thus we were interested in means allowing easily to decode, encode and parse Secondary Fields attributes. In the Microsoft.SharePoint.dll, there is the internal BdcClientUtil class containing the basic methods to work with Secondary Fields:

internal class BdcClientUtil
{
    ...
    string[] SplitStrings(string combinedEncoded);
    string   CombineStrings(string[] strings);
    ...
}

So, using .Net Reflector I’ve extracted these methods along with several others auxiliary ones and put them into the helper-class called SecondaryFieldNamesHelper. All internal methods and properties were honestly stolen from Microsoft.SharePoint.dll, the public ones were added by me and described below:

• string Encode(string[] secondaryFieldNames) – accepts an array of field names and returns the string formatted and encoded according to the SharePoint 2010 requirements;
• string[] Decode(string str) – accepts an encoded string, decodes it and returns a resultant array of field names;
• bool IsEncodedString(string str) – checks whether a passed string is encoded;
• string ConvertToSP2010(string str) – converts a SP 2007 colon-separated string of secondary fields into another one formatted and encoded according to the SharePoint 2010 requirements;

Below is the source code of the SecondaryFieldNamesHelper:

using System;
using System.Collections;
using System.Text;
using System.Globalization;
using System.IO;
using System.Web.UI;

namespace Helpers
{
    public static class SecondaryFieldNamesHelper
    {
        #region fields & properties
        private static string[] s_crgstrUrlHexValue = new string[] 
        { 
            "%00", "%01", "%02", "%03", "%04", "%05", "%06", "%07", "%08", "%09", "%0A", "%0B", "%0C", "%0D", "%0E", "%0F", 
            "%10", "%11", "%12", "%13", "%14", "%15", "%16", "%17", "%18", "%19", "%1A", "%1B", "%1C", "%1D", "%1E", "%1F", 
            "%20", "%21", "%22", "%23", "%24", "%25", "%26", "%27", "%28", "%29", "%2A", "%2B", "%2C", "%2D", "%2E", "%2F", 
            "%30", "%31", "%32", "%33", "%34", "%35", "%36", "%37", "%38", "%39", "%3A", "%3B", "%3C", "%3D", "%3E", "%3F", 
            "%40", "%41", "%42", "%43", "%44", "%45", "%46", "%47", "%48", "%49", "%4A", "%4B", "%4C", "%4D", "%4E", "%4F", 
            "%50", "%51", "%52", "%53", "%54", "%55", "%56", "%57", "%58", "%59", "%5A", "%5B", "%5C", "%5D", "%5E", "%5F", 
            "%60", "%61", "%62", "%63", "%64", "%65", "%66", "%67", "%68", "%69", "%6A", "%6B", "%6C", "%6D", "%6E", "%6F", 
            "%70", "%71", "%72", "%73", "%74", "%75", "%76", "%77", "%78", "%79", "%7A", "%7B", "%7C", "%7D", "%7E", "%7F", 
            "%80", "%81", "%82", "%83", "%84", "%85", "%86", "%87", "%88", "%89", "%8A", "%8B", "%8C", "%8D", "%8E", "%8F", 
            "%90", "%91", "%92", "%93", "%94", "%95", "%96", "%97", "%98", "%99", "%9A", "%9B", "%9C", "%9D", "%9E", "%9F", 
            "%A0", "%A1", "%A2", "%A3", "%A4", "%A5", "%A6", "%A7", "%A8", "%A9", "%AA", "%AB", "%AC", "%AD", "%AE", "%AF", 
            "%B0", "%B1", "%B2", "%B3", "%B4", "%B5", "%B6", "%B7", "%B8", "%B9", "%BA", "%BB", "%BC", "%BD", "%BE", "%BF", 
            "%C0", "%C1", "%C2", "%C3", "%C4", "%C5", "%C6", "%C7", "%C8", "%C9", "%CA", "%CB", "%CC", "%CD", "%CE", "%CF", 
            "%D0", "%D1", "%D2", "%D3", "%D4", "%D5", "%D6", "%D7", "%D8", "%D9", "%DA", "%DB", "%DC", "%DD", "%DE", "%DF", 
            "%E0", "%E1", "%E2", "%E3", "%E4", "%E5", "%E6", "%E7", "%E8", "%E9", "%EA", "%EB", "%EC", "%ED", "%EE", "%EF", 
            "%F0", "%F1", "%F2", "%F3", "%F4", "%F5", "%F6", "%F7", "%F8", "%F9", "%FA", "%FB", "%FC", "%FD", "%FE", "%FF"
        };
        #endregion

        #region public methods
        public static bool IsEncodedString(string str)
        {
            if (string.IsNullOrEmpty(str))
                return false;

            bool res = true;
            try
            {
                string[] splittedString = SplitStrings(str);
            }
            catch
            {
                res = false;
            }
            return res;
        }

        public static string Encode(string[] secondaryFieldNames)
        {
            return CombineStrings(secondaryFieldNames);
        }

        public static string[] Decode(string str)
        {
            if(string.IsNullOrEmpty(str))
                return new string[0];
            return SplitStrings(str);
        }

        public static string ConvertToSP2010(string str)
        {
            if (IsEncodedString(str))
                return str;

            string[] fieldNames = str.Split(new string[] { ":" }, StringSplitOptions.RemoveEmptyEntries);
            string encodedVal = CombineStrings(fieldNames);
            return encodedVal;
        }
        #endregion

        #region internal methods
        private static string[] SplitStrings(string combinedEncoded)
        {
            string[] array = null;
            ArrayList list = new ArrayList();
            if ("0" == combinedEncoded)
                return new string[0];
            try
            {
                string str = UrlKeyValueDecode(combinedEncoded);
                string[] strArray2 = str.Split(new char[] { ' ' }, StringSplitOptions.None);
                int result = 0;
                if ((strArray2 == null) || !int.TryParse(strArray2[strArray2.Length - 1], NumberStyles.Integer, 

CultureInfo.InvariantCulture, out result))
                    throw new ArgumentException(string.Empty, "combinedEncoded");
                int num2 = str.LastIndexOf(' ');
                string str2 = str.Substring(result, num2 - result);
                int length = str2.Length;
                int index = 0;
                int startIndex = 0;
                while (startIndex < length)
                {
                    string s = strArray2[index];
                    int num6 = 1;
                    if ((s != null) && (s.Length == 0))
                        list.Add(null);
                    else
                    {
                        if (!int.TryParse(s, NumberStyles.Integer, CultureInfo.InvariantCulture, out num6))
                            throw new ArgumentException(string.Empty, "combinedEncoded");
                        list.Add(str2.Substring(startIndex, num6 - 1));
                    }
                    startIndex += num6;
                    index++;
                }
                array = new string[list.Count];
                list.CopyTo(array);
            }
            catch (Exception exception)
            {
                throw new ArgumentException(string.Empty, "combinedEncoded", exception);
            }
            return array;
        }

        private static string UrlKeyValueDecode(string keyOrValueToDecode)
        {
            if (string.IsNullOrEmpty(keyOrValueToDecode))
                return keyOrValueToDecode;
            return UrlDecodeHelper(keyOrValueToDecode, keyOrValueToDecode.Length, true);
        }

        private static string UrlDecodeHelper(string stringToDecode, int length, bool decodePlus)
        {
            if ((stringToDecode == null) || (stringToDecode.Length == 0))
                return stringToDecode;
            StringBuilder builder = new StringBuilder(length);
            byte[] bytes = null;
            int nIndex = 0;
            while (nIndex < length)
            {
                char ch = stringToDecode[nIndex];
                if (ch < ' ')
                    nIndex++;
                else
                {
                    if (decodePlus && (ch == '+'))
                    {
                        builder.Append(" ");
                        nIndex++;
                        continue;
                    }
                    if (IsHexEscapedChar(stringToDecode, nIndex, length))
                    {
                        if (bytes == null)
                            bytes = new byte[(length - nIndex) / 3];
                        int count = 0;
                        do
                        {
                            int num3 = (FromHexNoCheck(stringToDecode[nIndex + 1]) * 0x10) + FromHexNoCheck(stringToDecode[nIndex + 

2]);
                            bytes[count++] = (byte)num3;
                            nIndex += 3;
                        }
                        while (IsHexEscapedChar(stringToDecode, nIndex, length));
                        builder.Append(Encoding.UTF8.GetChars(bytes, 0, count));
                        continue;
                    }
                    builder.Append(ch);
                    nIndex++;
                }
            }
            if (length < stringToDecode.Length)
                builder.Append(stringToDecode.Substring(length));
            return builder.ToString();
        }

        private static bool IsHexEscapedChar(string str, int nIndex, int nPathLength)
        {
            if ((((nIndex + 2) >= nPathLength) || (str[nIndex] != '%')) || (!IsHexDigit(str[nIndex + 1]) || !IsHexDigit(str[nIndex + 

2])))
                return false;
            if (str[nIndex + 1] == '0')
                return (str[nIndex + 2] != '0');
            return true;
        }

        private static bool IsHexDigit(char digit)
        {
            if ((('0' > digit) || (digit > '9')) && (('a' > digit) || (digit > 'f')))
                return (('A' <= digit) && (digit <= 'F'));
            return true;
        }

        private static int FromHexNoCheck(char digit)
        {
            if (digit <= '9')
                return (digit - '0');
            if (digit <= 'F')
                return ((digit - 'A') + 10);
            return ((digit - 'a') + 10);
        }

        private static string CombineStrings(string[] strings)
        {
            StringBuilder builder = new StringBuilder();
            int index = 0;
            for (int i = 0; i < strings.Length; i++)
            {
                string str = strings[i];
                string str2 = ((str != null) ? ((str.Length + 1)).ToString(CultureInfo.InvariantCulture) : string.Empty) + ' ';
                builder.Insert(index, str2);
                index += str2.Length;
                builder.Append(str + ' ');
            }
            builder.Append(index.ToString(CultureInfo.InvariantCulture));
            return UrlKeyValueEncode(builder.ToString());
        }

        private static string UrlKeyValueEncode(string keyOrValueToEncode)
        {
            if ((keyOrValueToEncode == null) || (keyOrValueToEncode.Length == 0))
                return keyOrValueToEncode;
            StringBuilder sb = new StringBuilder(0xff);
            HtmlTextWriter output = new HtmlTextWriter(new StringWriter(sb, CultureInfo.InvariantCulture));
            UrlKeyValueEncode(keyOrValueToEncode, output);
            return sb.ToString();
        }

        private static void UrlKeyValueEncode(string keyOrValueToEncode, TextWriter output)
        {
            if (((keyOrValueToEncode != null) && (keyOrValueToEncode.Length != 0)) && (output != null))
            {
                bool fUsedNextChar = false;
                int startIndex = 0;
                int length = 0;
                int num3 = keyOrValueToEncode.Length;
                for (int i = 0; i < num3; i++)
                {
                    char ch = keyOrValueToEncode[i];
                    if (((('0' <= ch) && (ch <= '9')) || (('a' <= ch) && (ch <= 'z'))) || (('A' <= ch) && (ch <= 'Z')))
                        length++;
                    else
                    {
                        if (length > 0)
                        {
                            output.Write(keyOrValueToEncode.Substring(startIndex, length));
                            length = 0;
                        }
                        UrlEncodeUnicodeChar(output, keyOrValueToEncode[i], (i < (num3 - 1)) ? keyOrValueToEncode[i + 1] : '\0', out 

fUsedNextChar);
                        if (fUsedNextChar)
                            i++;
                        startIndex = i + 1;
                    }
                }
                if ((startIndex < num3) && (output != null))
                    output.Write(keyOrValueToEncode.Substring(startIndex));
            }
        }

        private static void UrlEncodeUnicodeChar(TextWriter output, char ch, char chNext, out bool fUsedNextChar)
        {
            bool fInvalidUnicode = false;
            UrlEncodeUnicodeChar(output, ch, chNext, ref fInvalidUnicode, out fUsedNextChar);
        }

        private static void UrlEncodeUnicodeChar(TextWriter output, char ch, char chNext, ref bool fInvalidUnicode, out bool 

fUsedNextChar)
        {
            int num = 0xc0;
            int num2 = 0xe0;
            int num3 = 240;
            int num4 = 0x80;
            int num5 = 0xd800;
            int num6 = 0xfc00;
            int num7 = 0x10000;
            fUsedNextChar = false;
            int index = ch;
            if (index <= 0x7f)
                output.Write(s_crgstrUrlHexValue[index]);
            else
            {
                int num8;
                if (index <= 0x7ff)
                {
                    num8 = num | (index >> 6);
                    output.Write(s_crgstrUrlHexValue[num8]);
                    num8 = num4 | (index & 0x3f);
                    output.Write(s_crgstrUrlHexValue[num8]);
                }
                else if ((index & num6) != num5)
                {
                    num8 = num2 | (index >> 12);
                    output.Write(s_crgstrUrlHexValue[num8]);
                    num8 = num4 | ((index & 0xfc0) >> 6);
                    output.Write(s_crgstrUrlHexValue[num8]);
                    num8 = num4 | (index & 0x3f);
                    output.Write(s_crgstrUrlHexValue[num8]);
                }
                else if (chNext != '\0')
                {
                    index = (index & 0x3ff) << 10;
                    fUsedNextChar = true;
                    index |= chNext & 'Ͽ';
                    index += num7;
                    num8 = num3 | (index >> 0x12);
                    output.Write(s_crgstrUrlHexValue[num8]);
                    num8 = num4 | ((index & 0x3f000) >> 12);
                    output.Write(s_crgstrUrlHexValue[num8]);
                    num8 = num4 | ((index & 0xfc0) >> 6);
                    output.Write(s_crgstrUrlHexValue[num8]);
                    num8 = num4 | (index & 0x3f);
                    output.Write(s_crgstrUrlHexValue[num8]);
                }
                else
                    fInvalidUnicode = true;
            }
        }
        #endregion
    }
}

The SecondaryFieldNamesHelper can be used as shown below:

SPBusinessDataField bdcField = ...

string secondaryFieldWssNamesProperty = bdcField.GetProperty("SecondaryFieldWssNames");
string[] secondaryWssFieldNames = SecondaryFieldNamesHelper.Decode(property);

string secondaryFieldBdcNamesProperty = bdcField.GetProperty("SecondaryFieldBdcNames");
string[] secondaryFieldBdcNames = SecondaryFieldNamesHelper.Decode(secondaryFieldBdcNamesProperty);

string sp2010WssStaticNames = 
   SecondaryFieldNamesHelper.ConvertToSP2010("Product_x003a__x0020_Price:Product_x003a__x0020_Producer");

As a .cs file the SecondaryFieldNamesHelper class is available here.