[7] use of the injection framework roboguice: (your first custom binding)

In the previous article, we briefly introduced the use of roboguice ([6] use of the injection framework roboguice :( singletons and contextsingletons). Let's take a look at the binding ).

(1): using custom binding, We can bind a class or an interface to a subclass, instance or content provider (provinders ).

Now let's assume that:

public interface IFoo {}public class Foo implements IFoo {}

This custom binding allows you to bind an interface ifoo to the class Foo, and then create a foo instance for each annotation (@ inject ifoo.

public class MyActivity extends RoboActivity {    //How to tell RoboGuice to inject an instance of Foo ?    @Inject IFoo foo;}

(2): custom binding:

For custom binding, we need to create our own module (s). It is easy to create modules from roboguice 2.0.

①: Register modules in androidmanifset. xml

②: Create a class that inherits abstractmodule

2.1: Register modules in androidmanifset. xml

In androidmanifset. XML, add some meta-data tag fields and modules full names to the application tag, as shown below:

<application ...>    <meta-data android:name="roboguice.modules"               android:value="com.example.MyModule,com.example.MyModule2" />                </application>

2.2: Create a class that inherits abstractmodule

Each module must be registered before it is created. All of these modules are accessed through reflection. See the following instance code:

package com.example;public class MyModule extends AbstractModule {     //a default constructor is fine for a Module    public void bind() {        bind(IFoo.class).to(Foo.class);    }}public class MyModule2 extends AbstractModule {    //if your module requires a context, add a constructor that will be passed a context.    private Context context;    //with RoboGuice 3.0, the constructor for AbstractModule will use an `Application`, not a `Context`    public MyModule( Context context ) {        this.context = context;    }    public void bind() {        bind(IFoo.class).toInstance( new Foo(context));    }}

[7] use of the injection framework roboguice: (your first custom binding)