Since IField object may contain items and children subobjects, it might look complicated to iterate over the fields.

Use the following code to display all fields inside IDocument:

 private void AppendToResult(IField field, StringBuilder result)
 {
   if (field.Value != null)
   {
     result.AppendFormat("{0} = {1}\n", field.FullName, field.Value.AsText.Text);
     return;
   }
   if (field.Children != null)
   {
   foreach (IField childField in field.Children)
     {
       AppendToResult(childField, result);
     }
   }
 if (field.Instances != null) {
   foreach( IField instanceField in field.Instances)
   {
     AppendToResult(instanceField, result);
   }
  }
 }

 System.Text.StringBuilder result = new System.Text.StringBuilder();
 FCEngine.IField documentAsField = (IField)document;
 AppendToResult(documentAsField, result);