Windows Phone 上的XNA游戏编程学习笔记（1）--编写第一个手机小游戏

XNA（维基百科介绍）是微软开发的专门的游戏开发工具，用于开发Xbox游戏，也是windows phone 上的专业游戏开发平台。下面就是我编写的第一个XNA游戏，共享一下，纯属学习，大神神马的就别看了。

（1）下载并安装windows phone 的SDK(包含XNA framework )

http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=27153

（2）打开visual studio2010，文件|新建|项目…并选择XNA Game Studio 中的Windows Studio Game（4.0）。  

 

（3）建好工程之后，由于XNA是基于位图的程序，需要向工程中添加一些必要的文件，如使用的字体、以及使用到的图片。

先添加一个新的字体segoe（位图版的字体是有版权的，方便起见还是用系统自带的吧）。

并且添加位图football.png到工程中。（先下载，再Add| Existing Item..）

(4)之后，就可以向Game1.cs中添加代码。

将其中的Game1 类换成如下代码：

 1  public class Game1 : Microsoft.Xna.Framework.Game
 2  {
 3  GraphicsDeviceManager graphics;
 4  SpriteBatch spriteBatch;
 5  const float DECELERATION = 1000; // pixels per second squared
 6  Texture2D texture;
 7  RenderTarget2D tinyTexture;
 8  Vector2 position = Vector2.Zero;
 9  Vector2 velocity;
 10  SpriteFont segoe14;
 11  StringBuilder text = new StringBuilder();
 12  Viewport viewport;
 13  public Game1()
 14  {
 15  graphics = new GraphicsDeviceManager(this);
 16  Content.RootDirectory = "Content";
 17  // Frame rate is 30 fps by default for Windows Phone.
 18  TargetElapsedTime = TimeSpan.FromTicks(333333);
 19  TouchPanel.EnabledGestures = GestureType.Flick;
 20  }
 21 
 22  /// <summary>
 23  /// Allows the game to perform any initialization it needs to before starting to run.
 24  /// This is where it can query for any required services and load any non-graphic
 25  /// related content. Calling base.Initialize will enumerate through any components
 26  /// and initialize them as well.
 27  /// </summary>
 28  protected override void Initialize()
 29  {
 30  // TODO: Add your initialization logic here
 31 
 32  base.Initialize();
 33  }
 34 
 35  /// <summary>
 36  /// LoadContent will be called once per game and is the place to load
 37  /// all of your content.
 38  /// </summary>
 39  protected override void LoadContent()
 40  {
 41  // Create a new SpriteBatch, which can be used to draw textures.
 42  spriteBatch = new SpriteBatch(GraphicsDevice);
 43 
 44  tinyTexture = new RenderTarget2D(this.GraphicsDevice, 1, 1);
 45 
 46  this.GraphicsDevice.SetRenderTarget(tinyTexture);
 47  this.GraphicsDevice.Clear(Color.White);
 48  this.GraphicsDevice.SetRenderTarget(null);
 49 
 50  texture = this.Content.Load<Texture2D>("football");
 51  segoe14 = this.Content.Load<SpriteFont>("Segoe");
 52  }
 53 
 54  /// <summary>
 55  /// UnloadContent will be called once per game and is the place to unload
 56  /// all content.
 57  /// </summary>
 58  protected override void UnloadContent()
 59  {
 60  // TODO: Unload any non ContentManager content here
 61  }
 62 
 63  /// <summary>
 64  /// Allows the game to run logic such as updating the world,
 65  /// checking for collisions, gathering input, and playing audio.
 66  /// </summary>
 67  /// <param name="gameTime">Provides a snapshot of timing values.</param>
 68  protected override void Update(GameTime gameTime)
 69  {
 70  // Allows the game to exit
 71  if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit();
 72  // Set velocity from Flick gesture
 73  while (TouchPanel.IsGestureAvailable)
 74  {
 75  GestureSample gesture = TouchPanel.ReadGesture();
 76  if (gesture.GestureType == GestureType.Flick)
 77  velocity += gesture.Delta;
 78  }
 79  // Use velocity to adjust position and decelerate
 80  if (velocity != Vector2.Zero)
 81  {
 82  float elapsedSeconds = (float)gameTime.ElapsedGameTime.TotalSeconds;
 83  position += velocity * elapsedSeconds;
 84  viewport = this.GraphicsDevice.Viewport;
 85  while (true)
 86  {
 87  if (position.X < 0)
 88  {
 89  position.X = -position.X;
 90  velocity.X = -(float)0.8 * velocity.X;
 91  continue;
 92  }
 93  if (position.Y < 0)
 94  {
 95  position.Y = -position.Y;
 96  velocity.Y = -(float)0.8 * velocity.Y;
 97  continue;
 98  }
 99  if (position.X > viewport.Width - texture.Width)
100  {
101  position.X = 2 * (viewport.Width - texture.Width) - position.X;
102  velocity.X = -(float)0.8 * velocity.X;
103  continue;
104  }
105  if (position.Y > viewport.Height - texture.Height)
106  {
107  position.Y = 2 * (viewport.Height - texture.Height) - position.Y;
108  velocity.Y = -(float)0.8 * velocity.Y;
109  continue;
110  }
111  break;
112  }
113  float newMagnitude = velocity.Length() - DECELERATION * elapsedSeconds;
114  velocity.Normalize(); velocity *= Math.Max(0, newMagnitude);
115  }
116  // Display current position and velocity
117  text.Remove(0, text.Length);
118  text.AppendFormat("Position: {0} Velocity: {1}", position, velocity);
119  base.Update(gameTime);
120  }
121 
122  /// <summary>
123  /// This is called when the game should draw itself.
124  /// </summary>
125  /// <param name="gameTime">Provides a snapshot of timing values.</param>
126  protected override void Draw(GameTime gameTime)
127  {
128  GraphicsDevice.Clear(Color.CornflowerBlue);
129  spriteBatch.Begin();
130  spriteBatch.Draw(tinyTexture, new Rectangle(0, 0, 800, 480), Color.White);
131  spriteBatch.Draw(texture, position, Color.White);
132  spriteBatch.DrawString(segoe14, text, Vector2.Zero, Color.Blue);
133  spriteBatch.End();
134  base.Draw(gameTime);
135  }
136  }

（5）编译运行，在屏幕中出现一个足球，你可以通过鼠标模拟手指轻划屏幕，足球就会在屏幕中弹来弹去，直至速度为0；