【原创】Alex
在XNA游戏开发过程中，OPP思想尤为重要，它能实现组件的复用。将特定部分从程序主体中分离出来。
游戏开发与普通应用程序开发不同，每个游戏对象在运行过程中都会被更新Update或重绘Draw。因此分离出的对象必须要有自己的初始化方法（Initialize），LoadContent，Update，Draw，UnLoadContent方法。
在定义新类的最好方法是继承GameComponent类。这样做的目的是可将一个或多个新类的实例添加到Components集合中。每次游戏主体类如图AlexGame的Update方法被调用后，GameComponent的Update方法也会自动被调用。
如果需要绘制其他某些东西，还可以将新类继承DrawableGameComponent类。该类包含Draw方法。同样的游戏主体的Draw方法被调用后新类的Draw也被调用。
士兵类
代码
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using Microsoft.Xna.Framework;
6 using Microsoft.Xna.Framework.Audio;
7 using Microsoft.Xna.Framework.Content;
8 using Microsoft.Xna.Framework.GamerServices;
9 using Microsoft.Xna.Framework.Graphics;
10 using Microsoft.Xna.Framework.Input;
11 using Microsoft.Xna.Framework.Media;
12 using Microsoft.Xna.Framework.Net;
13 using Microsoft.Xna.Framework.Storage;
14
15 namespace Alex
16 {
17 class Soldier:GameComponent
18 {
19 public Soldier(Game game):base(game)
20 {
21
22 }
23 public override void Initialize()
24 {
25 base.Initialize();
26 }
27 public override void Update(GameTime gameTime)
28 {
29 base.Update(gameTime);
30 }
31
32 }
33 }
34
英雄类
代码
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using Microsoft.Xna.Framework;
6 using Microsoft.Xna.Framework.Audio;
7 using Microsoft.Xna.Framework.Content;
8 using Microsoft.Xna.Framework.GamerServices;
9 using Microsoft.Xna.Framework.Graphics;
10 using Microsoft.Xna.Framework.Input;
11 using Microsoft.Xna.Framework.Media;
12 using Microsoft.Xna.Framework.Net;
13 using Microsoft.Xna.Framework.Storage;
14 namespace Alex
15 {
16 class Hero:GameComponent
17 {
18 public Hero(Game game):base(game)
19 {
20 }
21 public override void Initialize()
22 {
23
24 base.Initialize();
25 }
26 public override void Update(GameTime gameTime)
27 {
28 base.Update(gameTime);
29 }
30 }
31 }
游戏主体类
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using Microsoft.Xna.Framework;
5 using Microsoft.Xna.Framework.Audio;
6 using Microsoft.Xna.Framework.Content;
7 using Microsoft.Xna.Framework.GamerServices;
8 using Microsoft.Xna.Framework.Graphics;
9 using Microsoft.Xna.Framework.Input;
10 using Microsoft.Xna.Framework.Media;
11 using Microsoft.Xna.Framework.Net;
12 using Microsoft.Xna.Framework.Storage;
13
14 namespace Alex
15 {
16 /// <summary>
17 /// This is the main type for your game
18 /// </summary>
19 public class AlexGame : Microsoft.Xna.Framework.Game
20 {
21 GraphicsDeviceManager graphics;
22 SpriteBatch spriteBatch;
23
24 public AlexGame()
25 {
26 graphics = new GraphicsDeviceManager(this);
27 Content.RootDirectory = "Content";
28 //游戏类初始化阶段将新类添加到组件中
29 this.Components.Add(new Hero(this));
30 this.Components.Add(new Soldier(this));
31 }
32
33 /// <summary>
34 /// Allows the game to perform any initialization it needs to before starting to run.
35 /// This is where it can query for any required services and load any non-graphic
36 /// related content. Calling base.Initialize will enumerate through any components
37 /// and initialize them as well.
38 /// </summary>
39 protected override void Initialize()
40 {
41 // TODO: Add your initialization logic here
42 this.TargetElapsedTime = TimeSpan.FromSeconds(1.0f / 1000.0f);
43 base.Initialize();
44 }
45
46 /// <summary>
47 /// LoadContent will be called once per game and is the place to load
48 /// all of your content.
49 /// </summary>
50 protected override void LoadContent()
51 {
52 // Create a new SpriteBatch, which can be used to draw textures.
53 spriteBatch = new SpriteBatch(GraphicsDevice);
54
55 // TODO: use this.Content to load your game content here
56 }
57
58 /// <summary>
59 /// UnloadContent will be called once per game and is the place to unload
60 /// all content.
61 /// </summary>
62 protected override void UnloadContent()
63 {
64 // TODO: Unload any non ContentManager content here
65 }
66
67 /// <summary>
68 /// Allows the game to run logic such as updating the world,
69 /// checking for collisions, gathering input, and playing audio.
70 /// </summary>
71 /// <param name="gameTime">Provides a snapshot of timing values.</param>
72 protected override void Update(GameTime gameTime)
73 {
74 // Allows the game to exit
75 if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
76 {
77 this.Exit();
78 }
79 if (Keyboard.GetState().IsKeyDown(Keys.Escape))
80 {
81 this.Exit();
82 }
83
84 // TODO: Add your update logic here
85
86 base.Update(gameTime);
87 }
88
89 /// <summary>
90 /// This is called when the game should draw itself.
91 /// </summary>
92 /// <param name="gameTime">Provides a snapshot of timing values.</param>
93 protected override void Draw(GameTime gameTime)
94 {
95 GraphicsDevice.Clear(Color.CornflowerBlue);
96 // TODO: Add your drawing code here
97
98 base.Draw(gameTime);
99 }
100 }
101 }
102
103
104在士兵类和英雄类中只是继承GameComponment父类。其运行过程大家可设置相应的断点进行调试。