// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_Attachments();

// Create an object of the Document class
Document doc = new Document();
// Initialize Page class object
Aspose.Note.Page page = new Aspose.Note.Page(doc);
// Initialize Outline class object
Outline outline = new Outline(doc);
// Initialize OutlineElement class object
OutlineElement outlineElem = new OutlineElement(doc);
// Initialize AttachedFile class object and also pass its icon path
AttachedFile attachedFile = new AttachedFile(doc, dataDir + "attachment.txt", File.OpenRead(dataDir  + "icon.jpg"), ImageFormat.Jpeg);
// Add attached file
outlineElem.AppendChildLast(attachedFile);
// Add outline element node
outline.AppendChildLast(outlineElem);
// Add outline node
page.AppendChildLast(outline);
// Add page node
doc.AppendChildLast(page);

dataDir = dataDir + "AttachFileAndSetIcon_out.one";
doc.Save(dataDir);