XNA游戏开发之(五)——XNA实现组件复用

 【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

 
 

  
  
  
  
  
  代码 
  
  
 
   
    
    

     
     
     
      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。