问题
I'm looking at the Ninject Factory extension at the following link: http://www.planetgeek.ch/2011/12/31/ninject-extensions-factory-introduction/
I'm trying to wrap my head around the extension and see if it actually fits into what I'm trying to do.
Can the factory extension create different types based on a parameter that is passed in?
Example:
class Base {}
class Foo : Base {}
class Bar : Base {}
interface IBaseFactory
{
Base Create(string type);
}
kernel.Bind<IBaseFactory>().ToFactory();
What I want to be able to do is this:
factory.Create("Foo") // returns a Foo
factory.Create("Bar") // returns a Bar
factory.Create("AnythingElse") // returns null or throws exception?
Can this extension do this or is this not really one of the intended uses?
回答1:
Sure - You can use your custom instance provider.
[Fact]
public void CustomInstanceProviderTest()
{
const string Name = "theName";
const int Length = 1;
const int Width = 2;
this.kernel.Bind<ICustomizableWeapon>().To<CustomizableSword>().Named("sword");
this.kernel.Bind<ICustomizableWeapon>().To<CustomizableDagger>().Named("dagger");
this.kernel.Bind<ISpecialWeaponFactory>().ToFactory(() => new UseFirstParameterAsNameInstanceProvider());
var factory = this.kernel.Get<ISpecialWeaponFactory>();
var instance = factory.CreateWeapon("sword", Length, Name, Width);
instance.Should().BeOfType<CustomizableSword>();
instance.Name.Should().Be(Name);
instance.Length.Should().Be(Length);
instance.Width.Should().Be(Width);
}
private class UseFirstParameterAsNameInstanceProvider : StandardInstanceProvider
{
protected override string GetName(System.Reflection.MethodInfo methodInfo, object[] arguments)
{
return (string)arguments[0];
}
protected override Parameters.ConstructorArgument[] GetConstructorArguments(System.Reflection.MethodInfo methodInfo, object[] arguments)
{
return base.GetConstructorArguments(methodInfo, arguments).Skip(1).ToArray();
}
}
来源:https://stackoverflow.com/questions/9416132/ninject-factory-on-derived-types