Usefel Tips For Windows Phone XNA Game Development

• The original: http://www.wpgamer.info/2013/04/several-keys-in-windows-phone-xna-game.html.

Introduction/Catalog

These two months I am developing XNA Game for Windows Phone 7. This was my first XNA programming, so I have a lot of headache problems, here I'll share with you.

• Do Not Create A Lot Of SpriteBatch
• Do Not Forget To Remove Events
• Use Local ContentManager
• Do Not Create A Lot Of SpriteBatch

At first, I set up a SpriteBatch object for each sprite in game, such as:

internal abstract class Spirit
 : DrawableGameComponent, ISpirit
{
 // ...
 
 protected override void LoadContent ( )
 {
  this.spiritBatch = new SpriteBatch ( this.scene.World.Game.GraphicsDevice );

  base.LoadContent ( );
 }
 
 // ...
}

It don't seem to have any problems at first, but about 10 minutes the game will throw a exception of memory out of range.

So, then I only create one SpriteBatch object in the whole game, and add it as a service.

this.spiritBatch = new SpriteBatch ( this.Game.GraphicsDevice );
this.Game.Services.AddService ( typeof ( SpriteBatch ), this.spiritBatch );

Then, the game did not appear errors when you create a SpriteBatch.

Do Not Forget To Remove Events

You need to explicitly remove event, such as:

internal abstract class Player
 : Spirit, ILiving, IUnmatchable, IHardenable
{

 // ...

 protected Player ( IPlayScene scene, string movieName,
  string extendMovieName, Pad pad, float speed,
  HitArea hitArea, int width, int height, int maxLife,
  double hardenSecond, double unmatchSecond )
  : base ( scene, movieName, extendMovieName, speed, hitArea, width, height )
 {

  // ...

  this.hardenEffect =
   new HardenEffect ( this, hardenSecond <= 0 ? 0.1 : hardenSecond );
  this.hardenEffect.Opened += this.hardenOpened;
  this.hardenEffect.Closed += this.hardenClosed;

  // ...

 }

 protected override void Dispose ( bool disposing )
 {

  try
  {
   this.hardenEffect.Opened -= this.hardenOpened;
   this.hardenEffect.Closed -= this.hardenClosed;
  }
  catch { }

  base.Dispose ( disposing );
 }

 // ...

}

The Dispose method of Player class removed the events which are added in the constructor. If you just add event, but do not remove it, also may cause memory out of range.

Use Local ContentManager

Use the ContentManager, you can unload the resources no longer need, so you can save some memory.

this.contentManager =
 new ContentManager ( this.World.Game.Services, contentDirectory );

// ...

this.contentManager.Load<texture2d> ( resource.Path )

// ...

this.contentManager.Unload ( );