C# XNA 3D 模型未呈现

模型是一个 .fbx我也尝试了许多模型，似乎没有任何工作，我想知道是否有人可以帮助我，以下代码就是我要感谢的！

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace _3D
{
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        Model model;
        Matrix[] transforms;
        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
            graphics.PreferredBackBufferHeight = 800;
            graphics.PreferredBackBufferWidth = 1280;
        }
        protected override void Initialize()
        {
            base.Initialize();
        }
        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);
            model = Content.Load<Model>("3d/screwdriver");
            transforms = new Matrix[model.Bones.Count];
            model.CopyAbsoluteBoneTransformsTo(transforms);
        }
        protected override void UnloadContent()
        {
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            base.Update(gameTime);
        }    
        // The draw method is one of the reasons I think nothing is working,
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            Matrix view = Matrix.CreateLookAt(
                new Vector3(200, 300, 900),
                new Vector3(0, 50, 0),
                Vector3.Up);
            Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45), GraphicsDevice.Viewport.AspectRatio, 0.1f, 10000.0f);
            Matrix baseWorld = Matrix.CreateScale(0.4f) * Matrix.CreateRotationY(MathHelper.ToRadians(180));
            foreach (ModelMesh mesh in model.Meshes)
            {
                Matrix localWorld = transforms[mesh.ParentBone.Index] * baseWorld;
                foreach (ModelMeshPart part in mesh.MeshParts)
                { 
                BasicEffect e = (BasicEffect)part.Effect;
                e.World = localWorld;
                e.View = view;
                e.Projection = projection;
                e.EnableDefaultLighting();
                }
                mesh.Draw();
            }
            base.Draw(gameTime);
        }
    }
}