背景

创建一个属于自己的Ribbon按钮（如下图）
理解Ribbon、Panel、Tab的关系（如下图），一个Tab包含多个Panel，一个Panel包含多个RibbonButton

代码

using Autodesk.AutoCAD.Runtime;
using Autodesk.Windows;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Interop;
using System.Windows.Media.Imaging;

[assembly:CommandClass(typeof(CADBlogDemo.Ribbon))]
namespace CADBlogDemo
{
    public class Ribbon
    {
        [CommandMethod("RibbonCmd")]
        public void RibbonCmd()
        {
            //得到所有的Ribbon选项卡列表集合
            RibbonControl ribbonCtrl = ComponentManager.Ribbon;
            if (ribbonCtrl == null) return;
            //加个判断，如果有了这个选项卡就不重复添加
            if (ribbonCtrl.Tabs.FirstOrDefault(x => x.Title == "MyRibbon") != null) return;
            //添加选项卡
            RibbonTab tab = AddTab(ribbonCtrl, "MyRibbon", "RibbonId1", true);
            //添加面板
            RibbonPanelSource panel = AddPanel(tab, "我就是我");
            //添加按钮
            RibbonButton button = CreateRibbonButton(panel, "点我\n点我", "Demo\n", $@"{Path.GetDirectoryName(typeof(Ribbon).Assembly.Location)}\Images\123.png");
        }

        /// <summary>
        /// 添加Ribbon选项卡
        /// </summary>
        /// <param name="ribbonCtrl">Ribbon控制器</param>
        /// <param name="title">选项卡标题</param>
        /// <param name="id">选项卡ID</param>
        /// <param name="isActive">是否置为当前</param>
        /// <returns>RibbonTab</returns>
        public RibbonTab AddTab( RibbonControl ribbonCtrl, string title, string id, bool isActive)
        {
            RibbonTab tab = new RibbonTab();
            tab.Title = title;
            tab.Id = id;
            ribbonCtrl.Tabs.Add(tab);
            tab.IsActive = isActive;
            return tab;
        }
        /// <summary>
        /// 添加面板
        /// </summary>
        /// <param name="tab">Ribbon选项卡</param>
        /// <param name="title">面板标题</param>
        /// <returns>RibbonPanelSource</returns>
        public RibbonPanelSource AddPanel(RibbonTab tab, string title)
        {
            RibbonPanelSource panelSource = new RibbonPanelSource();
            panelSource.Title = title;
            RibbonPanel ribbonPanel = new RibbonPanel();
            ribbonPanel.Source = panelSource;
            tab.Panels.Add(ribbonPanel);
            return panelSource;
        }
        /// <summary>
        /// 创建按钮
        /// </summary>
        /// <param name="panel">面板</param>
        /// <param name="name">按钮显示名字</param>
        /// <param name="cmd">需要绑定的命令</param>
        /// <param name="photoPath">图片路径</param>
        /// <returns></returns>
        public RibbonButton CreateRibbonButton(RibbonPanelSource panel, string name, string cmd, string photoPath)
        {
            RibbonButton button = new RibbonButton();
            button.Text = name;
            button.ShowText = true;
            Bitmap bitmap = new Bitmap(photoPath);
            BitmapSource bitmapSource = Imaging.CreateBitmapSourceFromHBitmap(bitmap.GetHbitmap(), IntPtr.Zero, System.Windows.Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
            button.Image = bitmapSource; //按钮图片
            button.LargeImage = bitmapSource; //按钮大图片
            button.Size = RibbonItemSize.Large;
            button.Orientation = System.Windows.Controls.Orientation.Vertical;
            button.CommandHandler = new RibbonCommandHandler();
            button.CommandParameter = cmd;
            panel.Items.Add(button);
            return button;
        }
    }
    public class RibbonCommandHandler : System.Windows.Input.ICommand
    {
        public bool CanExecute(object parameter)
        {
            return true;
        }

        public event EventHandler CanExecuteChanged;

        public void Execute(object parameter)
        {
            //is from Ribbon Button
            RibbonButton ribBtn = parameter as RibbonButton;
            if (ribBtn != null)
            {
                //execute the command 
                Autodesk.AutoCAD.ApplicationServices.Application
                  .DocumentManager.MdiActiveDocument
                  .SendStringToExecute(
                     (string)ribBtn.CommandParameter, true, false, true);
            }
        }
    }
}

讲解

先得到所有的Tab列表集合，判断是否已经存在自己的选项卡了

 			//得到所有的Ribbon选项卡列表集合
            RibbonControl ribbonCtrl = ComponentManager.Ribbon;
            if (ribbonCtrl == null) return;

新建选项卡（Tab）

/// <summary>
        /// 添加Ribbon选项卡
        /// </summary>
        /// <param name="ribbonCtrl">Ribbon控制器</param>
        /// <param name="title">选项卡标题</param>
        /// <param name="id">选项卡ID</param>
        /// <param name="isActive">是否置为当前</param>
        /// <returns>RibbonTab</returns>
        public RibbonTab AddTab( RibbonControl ribbonCtrl, string title, string id, bool isActive)
        {
            RibbonTab tab = new RibbonTab();
            tab.Title = title;
            tab.Id = id;
            ribbonCtrl.Tabs.Add(tab);
            tab.IsActive = isActive;
            return tab;
        }

新建面板（panel）

/// <summary>
        /// 添加面板
        /// </summary>
        /// <param name="tab">Ribbon选项卡</param>
        /// <param name="title">面板标题</param>
        /// <returns>RibbonPanelSource</returns>
        public RibbonPanelSource AddPanel(RibbonTab tab, string title)
        {
            RibbonPanelSource panelSource = new RibbonPanelSource();
            panelSource.Title = title;
            RibbonPanel ribbonPanel = new RibbonPanel();
            ribbonPanel.Source = panelSource;
            tab.Panels.Add(ribbonPanel);
            return panelSource;
        }

新建按钮（Ribbon）

        /// <summary>
        /// 创建按钮
        /// </summary>
        /// <param name="panel">面板</param>
        /// <param name="name">按钮显示名字</param>
        /// <param name="cmd">需要绑定的命令</param>
        /// <param name="photoPath">图片路径</param>
        /// <returns></returns>
        public RibbonButton CreateRibbonButton(RibbonPanelSource panel, string name, string cmd, string photoPath)
        {
            RibbonButton button = new RibbonButton();
            button.Text = name;
            button.ShowText = true;
            Bitmap bitmap = new Bitmap(photoPath);
            BitmapSource bitmapSource = Imaging.CreateBitmapSourceFromHBitmap(bitmap.GetHbitmap(), IntPtr.Zero, System.Windows.Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
            button.Image = bitmapSource; //按钮图片
            button.LargeImage = bitmapSource; //按钮大图片
            button.Size = RibbonItemSize.Large;
            button.Orientation = System.Windows.Controls.Orientation.Vertical;
            button.CommandHandler = new RibbonCommandHandler();
            button.CommandParameter = cmd;
            panel.Items.Add(button);
            return button;
        }

RibbonCommandHandler类
继承于ICommand类，作用是控制按钮是否可用

    public class RibbonCommandHandler : System.Windows.Input.ICommand
    {
        public bool CanExecute(object parameter)
        {
            return true;
        }

        public event EventHandler CanExecuteChanged;

        public void Execute(object parameter)
        {
            //is from Ribbon Button
            RibbonButton ribBtn = parameter as RibbonButton;
            if (ribBtn != null)
            {
                //execute the command 
                Autodesk.AutoCAD.ApplicationServices.Application
                  .DocumentManager.MdiActiveDocument
                  .SendStringToExecute(
                     (string)ribBtn.CommandParameter, true, false, true);
            }
        }
    }