c# cad加载图片

以下是使用C#在AutoCAD中加载图片的示例代码：

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.Windows;
using System;

namespace LoadImage
{
    public class Commands
    {
        [CommandMethod("LoadImage")]
        public void LoadImage()
        {
            // 获取当前文档和数据库
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;

            // 打开图像文件
            PromptOpenFileOptions opts = new PromptOpenFileOptions("选择图像文件");
            opts.Filter = "图像文件 (*.bmp;*.jpg;*.jpeg;*.png)|*.bmp;*.jpg;*.jpeg;*.png";
            PromptFileNameResult result = doc.Editor.GetFileNameForOpen(opts);
            if (result.Status != PromptStatus.OK)
            {
                return;
            }

            // 创建图像对象
            ImageDef imgDef = new ImageDef();
            imgDef.SourceFileName = result.StringResult;
            imgDef.Load();

            // 获取当前空间
            BlockTableRecord space = (BlockTableRecord)db.CurrentSpaceId.GetObject(OpenMode.ForWrite);

            // 创建图像对象的参照
            ImageDefReactor reactor = new ImageDefReactor();
            reactor.ImageDefId = imgDef.ObjectId;            space.AppendEntity(reactor);
            db.TransactionManager.AddNewlyCreatedDBObject(reactor, true);

            // 创建图像参照
            Point3d insPt = new Point3d(0, 0, 0);
            double width = imgDef.Size.X;
            double height = imgDef.Size.Y;
            Vector3d u = new Vector3d(1, 0, 0);
            Vector3d v = new Vector3d(0, 1, 0);
            using (Image img = new Image())
            {
                img.ImageDefId = imgDef.ObjectId;
                img.Position = insPt;
                img.Width = width;
                img.Height = height;
                img.Orientation = new Matrix3d(u, v, Vector3d.ZAxis, insPt);
                space.AppendEntity(img);
                db.TransactionManager.AddNewlyCreatedDBObject(img, true);
            }

            // 提交事务
            db.TransactionManager.QueueForGraphicsFlush();
            db.TransactionManager.FlushGraphics();
        }
    }
}

这段代码使用了AutoCAD的API，通过选择图像文件，创建图像对象和图像参照，并将其添加到当前空间中。你可以将这段代码编译为dll文件，然后在AutoCAD中使用netload命令加载该插件。