/V4/PrismLibrary/Desktop/Prism/ServiceLocatorExtensions.cs

//===================================================================================

// Microsoft patterns & practices

// Composite Application Guidance for Windows Presentation Foundation and Silverlight

//===================================================================================

// Copyright (c) Microsoft Corporation.  All rights reserved.

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT

// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

// FITNESS FOR A PARTICULAR PURPOSE.

//===================================================================================

// The example companies, organizations, products, domain names,

// e-mail addresses, logos, people, places, and events depicted

// herein are fictitious.  No association with any real company,

// organization, product, domain name, email address, logo, person,

// places, or events is intended or should be inferred.

//===================================================================================

using System;

using Microsoft.Practices.ServiceLocation;



namespace Microsoft.Practices.Prism

{

    /// <summary>

    /// Defines extension methods for the <see cref="ServiceLocator"/> class.

    /// </summary>

    public static class ServiceLocatorExtensions

    {

        /// <summary>

        /// Attempts to resolve specified type from the underlying <see cref="IServiceLocator"/>.

        /// </summary>

        /// <remarks>

        /// This will return null on any <see cref="ActivationException"/>.</remarks>

        /// <param name="locator">Locator to use in resolving.</param>

        /// <param name="type">Type to resolve.</param>

        /// <returns>T or null</returns>

        /// <exception cref="ArgumentNullException">Thrown when <paramref name="locator"/> is <see langword="null"/>.</exception>

        public static object TryResolve(this IServiceLocator locator, Type type)

        {

            if (locator == null) throw new ArgumentNullException("locator");



            try

            {

                return locator.GetInstance(type);

            }

            catch (ActivationException)

            {

                return null;

            }

        }



        /// <summary>

        /// Attempts to resolve specified type from the underlying <see cref="IServiceLocator"/>.

        /// </summary>

        /// <remarks>

        /// This will return null on any <see cref="ActivationException"/>.</remarks>

        /// <typeparam name="T">Type to resolve.</typeparam>

        /// <param name="locator">Locator to use in resolving.</param>

        /// <returns>T or null</returns>

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1004:GenericMethodsShouldProvideTypeParameter")]

        public static T TryResolve<T>(this IServiceLocator locator) where T : class

        {

            return locator.TryResolve(typeof(T)) as T;

        }

    }

}