Beginner's guide to adding tab and button with Revit API

This video is a beginner's guide to how to add a tab and button to Revit through the API.  The documentation can be found on Autodesk website.  I've also provided the sample code I used in the video.

Tips:

• Add "References" by right clicking and going to "Add References" under "Framework" you'll find the "PresentationCore", "System.Xaml", "System.Xml", and "WindowsBase".
• MyTest.addin remove the <AddIn Type="Command"> and it's entire setup.  This is for the drop down Add-in for Revit. 

Sample Code:

#region Namespaces
using Autodesk.Revit.UI;
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Windows.Media.Imaging;
#endregion

namespace MyTest
{
    class App : IExternalApplication
    {
        public Result OnStartup(UIControlledApplication a)
        {
    // Method to add Tab and Panel 
            RibbonPanel panel = ribbonPanel(a);
    // Reflection to look for this assembly path 
            string thisAssemblyPath = Assembly.GetExecutingAssembly().Location;
    // Add button to panel 
            PushButton button = panel.AddItem(new PushButtonData("Button", "Test Button", thisAssemblyPath, "MyTest.Command")) as PushButton;
    // Add tool tip 
            button.ToolTip = "this is a sample";
    // Reflection of path to image 
            var globePath = System.IO.Path.Combine(System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location), "LACMA DOORS.png");
            Uri uriImage = new Uri(globePath);
    // Apply image to bitmap
            BitmapImage largeImage = new BitmapImage(uriImage);
    // Apply image to button 
            button.LargeImage = largeImage;

            a.ApplicationClosing += a_ApplicationClosing;

            //Set Application to Idling
            a.Idling += a_Idling;

            return Result.Succeeded;
        }
//*****************************a_Idling()*****************************
        void a_Idling(object sender, Autodesk.Revit.UI.Events.IdlingEventArgs e)
        {

        }
//*****************************a_ApplicationClosing()*****************************
        void a_ApplicationClosing(object sender, Autodesk.Revit.UI.Events.ApplicationClosingEventArgs e)
        {
            throw new NotImplementedException();
        }
//*****************************ribbonPanel()*****************************
        public RibbonPanel ribbonPanel(UIControlledApplication a)
        {
    // Tab name 
            string tab = "My Test Tab";
    // Empty ribbon panel 
            RibbonPanel ribbonPanel = null;
// Try to create ribbon tab. 
            try
            {
                //a.CreateRibbonPanel("My Test Tools");
                a.CreateRibbonTab(tab);
            }
            catch { }
    // Try to create ribbon panel. 
            try
            {
                RibbonPanel panel = a.CreateRibbonPanel(tab , "test");
            }
            catch { }
    // Search existing tab for your panel. 
            List<RibbonPanel> panels = a.GetRibbonPanels(tab);
            foreach(RibbonPanel p in panels)
            {
                if (p.Name == "test")
                {
                    ribbonPanel = p;
                }
            }
    //return panel 
            return ribbonPanel;
        }

        public Result OnShutdown(UIControlledApplication a)
        {
            return Result.Succeeded;
        }
    }
}