[code language="csharp"]
/*
 * Created by SharpDevelop.
 * User: Jay Merlan
 * Date: 3/12/2019
 * Time: 7:07 AM
 * 
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
using Autodesk.Revit.UI;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI.Selection;
using System.Collections.Generic;
using System.Linq;

namespace FirstModule
{
    [Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Manual)]
    [Autodesk.Revit.DB.Macros.AddInId("11B5DF7E-A80F-4038-88EA-7E3F9E2AEF9A")]
    public partial class ThisDocument
    {
        private void Module_Startup(object sender, EventArgs e)
        {
            // This method is called when a module is loaded
        }

        private void Module_Shutdown(object sender, EventArgs e)
        {
            // This method is called when a module unloads
        }

        #region Revit Macros generated code
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(Module_Startup);
            this.Shutdown += new System.EventHandler(Module_Shutdown);
        }
        #endregion

        public void HelloWorld()
        {
            // Get the active view of the current document.
            // http://www.revitapidocs.com/2018/043960ac-dde4-0f45-249f-8161646a4362.htm
            Autodesk.Revit.DB.View view = this.ActiveView;
            
            // Create XYZ object at coordinates x=0, y=0, z=0
            // http://www.revitapidocs.com/2018/c2fd995c-95c0-58fb-f5de-f3246cbc5600.htm
            XYZ noteCoordinates = new XYZ(0, 0, 0);
            
            // Create string object for text note
            // http://msdn2.microsoft.com/en-us/library/s1wwdcbf
            string content = "Hello world!";
            
            // Create a transaction so that we can modify the model
            // http://www.revitapidocs.com/2018/308ebf8d-d96d-4643-cd1d-34fffcea53fd.htm
            Transaction trans = new Transaction(this.Document, "Add text note");
            
            // Start the transaction
            trans.Start();
            
            // Get text note type by name
            ElementId textNoteTypeId = GetTextTypeIdByName(this.Document, "3/32\" Arial");
            
            // Create text options from text note type ID
            TextNoteOptions textNoteOptions = new TextNoteOptions(textNoteTypeId);
            
            // Create text note in view
            TextNote newTextNote = TextNote.Create(this.Document, view.Id, noteCoordinates, content, textNoteTypeId);
            
            // Commit the transaction change
            trans.Commit();
        }
        
        ///

        /// A helper method to return the element ID of a TextNoteType
        /// 

///The name of the text note type. /// The Element.Id of the TextNoteType. public static ElementId GetTextTypeIdByName(Document doc, string name) { ElementId textId = null; // Collect all text note types FilteredElementCollector collector = new FilteredElementCollector(doc); ICollection textNoteTypes = collector.OfClass(typeof(TextNoteType)) .ToElementIds() .ToList(); // Get text note types as elements List elements = new List(); foreach (ElementId noteId in textNoteTypes) { elements.Add(doc.GetElement(noteId)); } // Get the text note type element ID by name foreach (Element e in elements) { if (e.Name == name) textId = e.Id; } return textId; } } } [/code]