绑定ToConstant并调用InSingletonScope是多余的？

Question

嗯，标题很简单地说明了这个问题。

对于局部变量factory：

var factory = Fluently.Configure()
...

这两行是否相同：

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

和

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

Answer 1

在最新版本的ninject中，当您创建ToConstant绑定时，它会自动将Scope设置为Singleton。因此，示例中的InSingletonScope()部分是多余的。来自ninject代码库：

    /// <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;
    }