First, Open the Orchestration Designer for the Orchestration.

Go to the Orchestration View.

1. Create a variable of type System.Xml.XmlDocument, name it "xmlDocument."

2. Create an expression shape.

3. Assign the message variable which you want to log into the EventLog.

4. Use the property xmlDocument.OuterXML.

Figure 1: The Expression Shape

Notice the Expression shape in the figure given below.

Figure 2: The Expression Editor

For example:

xmlDocument = MsgEchoIn;
System.Diagnostics.EventLog.WriteEntry("Message XML", xmlDocument.OuterXML);