Loading Content Within a Game Library

项目
09/29/2011

It may be desirable in some designs to load and draw content within the methods of a Game Library. For example, you may wish to distribute code that displays textures, models, or fonts (such as a DrawableGameComponent) in a .DLL.

There are two techniques that accomodate this, one in which the binary content is separate from the .DLL, and one in which the content is embedded within the .DLL.

Loading Content in a Game Library
Embedding Content in a Game Library

Loading Content in a Game Library

In this method, the compiled content used by the game library is distributed in its own .xnb files, separate from the .DLL.

This is the preferred method in most cases, as it makes the most efficient use of memory, especially when binary content is large.

To create compiled content

Create a new solution that contains a game library project.
Add a game content project to the solution.
Add game assets to the content project.
Select the game library project, then right-click and choose Add Content Reference..., and select the game content project you just created.

When the solution is built, the resources in the content project will be compiled into binary .xnb files. These files will reside in the "bin\x86\Debug\Content" directory of the game library project (if built as an x86 debug project).

To load compiled content within the Game Library

Create a new class that is the child of DrawableGameComponent.
Define a new ContentManager and, within the constructor of the new class, set its RootDirectory to the path where the compiled content is to be stored.

For flexibility, the path string may be a parameter passed to the constructor by the game client.
```
public static ContentManager LibContent;

public GameLibComponent(Game game, string contentdirectory) : base(game)
{
    LibContent = new ContentManager(game.Services);
    LibContent.RootDirectory = contentdirectory;
}
```

In the LoadContent method, load your content normally using your ContentManager.

SpriteBatch spriteBatch;
Texture2D LibTexture;

protected override void LoadContent()
{
    spriteBatch = new SpriteBatch(GraphicsDevice);
    LibTexture = LibContent.Load<Texture2D>("mytexture");
}

Embedding Content in a Game Library

You may also embed binary content resources directly in the Game Library and load them from within. This technique requires the declaration of those resources in a reference file. It allows you to distribute code that displays textures, models, or fonts (such as a DrawableGameComponent) in a .DLL without distributing the .xnb files separately.

Important

Be aware that all embedded resources are loaded into memory with the .DLL, and cannot be unloaded from main memory. For this reason, this technique is not recommended for most applications, and should only be used when the content to embed is very small.

To add content to a Game Library as references

Build an existing project containing the content you wish to add.
In a library project, choose Add, New Item, and select "Resources File."
If the Resource Designer is not opened automatically, double-click the .resx file in the Solution Explorer.
From the Resource Designer, choose Add Resource, Add Existing File.
Navigate to the "bin\x86\Debug\Content" directory of the project that built the content you wish to add.

This assumes it was built as an x86 Debug project.
Select the .xnb files for the content you wish to add to the library.

Ensure the dialog box is displaying "All Files."

Once content has been added to the Resource Designer, any code running from within the Library can load the content with a special ContentManager.

To load embedded content within a Game Library

Create a new class that is the child of DrawableGameComponent.
Define a new ContentManager
Within the constructor of the new class, create a new instance of the ResourceContentManager class and assign it to your ContentManager.

The second parameter to the ResourceContentManager constructor identifies the resource project that contains your embedded resources.
```
public static ContentManager LibContent;

public GameLibComponent(Game game)
    : base(game)
{
    ResourceContentManager resxContent;
    resxContent = new ResourceContentManager(game.Services, ResourceFile.ResourceManager);
    LibContent = resxContent;
}
```