Here is technique for generating an instance of a BizTalk message (a.k.a, XmlDocument) based on a deployed schema.  It requires references to the following assemblies:

In a class library that has references to the above libraries, create a public class with the following two public methods:

using System;

using System.Collections.Generic;

using System.Text;

using System.Xml;

using Microsoft.BizTalk.Component.Interop;

using Microsoft.BizTalk.ExplorerOM;

 

namespace Spike.Sandbox

{

public class Utilities

{

/// <summary>

/// Build a BizTalk message for a single root node message

/// </summary>

/// <param name="schemaName"></param>

/// <returns></returns>

public static XmlDocument CreateBTSMessage(string schemaName)

{

return CreateMessage(schemaName, schemaName);

}

 

/// <summary>

/// Build a BizTalk Message for a multi-root node message

/// </summary>

/// <param name="schemaName"></param>

/// <param name="rootNode"></param>

/// <returns></returns>

public static XmlDocument CreateBTSMessage(string schemaName, string rootNode)

{

return CreateMessage(schemaName, string.Format("{0}+{1}", schemaName, rootNode));

}

These two methods call a private method that accesses the BizTalk management database to retrieve a deployed schema and construct the message:

private static XmlDocument CreateMessage(string schemaName, string rootNode)

{

XmlDocument doc = new XmlDocument();

DocumentSpec docSpec;

 

BtsCatalogExplorer catalog = new BtsCatalogExplorer();

catalog.ConnectionString = "Data Source=myServer;Initial Catalog=BizTalkMgmtDb2;Integrated Security=True";

Schema schema = catalog.Schemas[schemaName];

if (schema != null)

{

docSpec = new DocumentSpec(rootNode, schema.BtsAssembly.DisplayName);

if (docSpec != null)

{

StringBuilder sb = new StringBuilder();

StringWriter sw = new StringWriter(sb);

 

try

{

doc.Load(docSpec.CreateXmlInstance(sw));

}

finally

{

sw.Dispose();

}

}

}

 

return doc;

}

Cheers to Tomas Restrepo for his insight into the CreateXmlInstance: http://www.winterdom.com/weblog/2008/07/16/CreateXmlInstanceWithMultiRootSchemas.aspx