Is binding ToConstant and calling InSingletonScope redundant?

问题

Well, this question is pretty simply stated by the title.

For a local variable factory:

var factory = Fluently.Configure()
...

Are these two lines equivalent:

Bind<ISessionFactory>().ToConstant(factory).InSingletonScope();

and:

Bind<ISessionFactory>().ToConstant(factory);

回答1:

In the latest version of ninject, when you create a ToConstant binding it will automatically set the Scope to Singleton. Thus, the InSingletonScope() part in your example is redundant. From ninject code base:

    /// <summary>
    /// Indicates that the service should be bound to the specified constant value.
    /// </summary>
    /// <param name="value">The constant value.</param>
    public IBindingWhenInNamedWithOrOnSyntax<T> ToConstant(T value)
    {
        Binding.ProviderCallback = ctx => new ConstantProvider<T>(value);
        Binding.Target = BindingTarget.Constant;
        Binding.ScopeCallback = StandardScopeCallbacks.Singleton;

        return this;
    }

来源：https://stackoverflow.com/questions/7395071/is-binding-toconstant-and-calling-insingletonscope-redundant