Common Service Locator Interface

/// <summary>
/// The generic Service Locator interface. This interface is used
/// to retrieve services (instances identified by type and optional
/// name) from a container.
/// </summary>
[CLSCompliant(true)]
public interface IServiceLocator : IServiceProvider
{
    /// <summary>
    /// Get an instance of the given <paramref name="serviceType"/>.
    /// </summary>
    /// <param name="serviceType">Type of object requested.</param>
    /// <exception cref="ActivationException">if there is an error resolving
    /// the service instance.</exception>
    /// <returns>The requested service instance.</returns>
    object GetInstance(Type serviceType);

    /// <summary>
    /// Get an instance of the given named <paramref name="serviceType"/>.
    /// </summary>
    /// <param name="serviceType">Type of object requested.</param>
    /// <param name="key">Name the object was registered with.</param>
    /// <exception cref="ActivationException">if there is an error resolving
    /// the service instance.</exception>
    /// <returns>The requested service instance.</returns>
    object GetInstance(Type serviceType, string key);

    /// <summary>
    /// Get all instances of the given <paramref name="serviceType"/> currently
    /// registered in the container.
    /// </summary>
    /// <param name="serviceType">Type of object requested.</param>
    /// <exception cref="ActivationException">if there is are errors resolving
    /// the service instance.</exception>
    /// <returns>A sequence of instances of the requested <paramref name="serviceType"/>.</returns>
    IEnumerable<object> GetAllInstances(Type serviceType);

    /// <summary>
    /// Get an instance of the given <typeparamref name="TService"/>.
    /// </summary>
    /// <typeparam name="TService">Type of object requested.</typeparam>
    /// <exception cref="ActivationException">if there is are errors resolving
    /// the service instance.</exception>
    /// <returns>The requested service instance.</returns>
    TService GetInstance<TService>();

    /// <summary>
    /// Get an instance of the given named <typeparamref name="TService"/>.
    /// </summary>
    /// <typeparam name="TService">Type of object requested.</typeparam>
    /// <param name="key">Name the object was registered with.</param>
    /// <exception cref="ActivationException">if there is are errors resolving
    /// the service instance.</exception>
    /// <returns>The requested service instance.</returns>
    TService GetInstance<TService>(string key);

    /// <summary>
    /// Get all instances of the given <typeparamref name="TService"/> currently
    /// registered in the container.
    /// </summary>
    /// <typeparam name="TService">Type of object requested.</typeparam>
    /// <exception cref="ActivationException">if there is are errors resolving
    /// the service instance.</exception>
    /// <returns>A sequence of instances of the requested <typeparamref name="TService"/>.</returns>
    IEnumerable<TService> GetAllInstances<TService>();
}