/V2.2/trunk/CAL/Desktop/Composite/Modularity/AssemblyResolver.Desktop.cs
C# | 155 lines | 95 code | 25 blank | 35 comment | 15 complexity | b1b70a69f43c817dacbecb5e9c7bf47a MD5 | raw file
- //===================================================================================
- // 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 System.Collections.Generic;
- using System.IO;
- using System.Linq;
- using System.Reflection;
- using System.Security.Permissions;
- using Microsoft.Practices.Composite.Properties;
-
- namespace Microsoft.Practices.Composite.Modularity
- {
- /// <summary>
- /// Handles AppDomain's AssemblyResolve event to be able to load assemblies dynamically in
- /// the LoadFrom context, but be able to reference the type from assemblies loaded in the Load context.
- /// </summary>
- [SecurityPermission(SecurityAction.LinkDemand)]
- [SecurityPermission(SecurityAction.InheritanceDemand)]
- public class AssemblyResolver : IAssemblyResolver, IDisposable
- {
- private readonly List<AssemblyInfo> registeredAssemblies = new List<AssemblyInfo>();
-
- private bool handlesAssemblyResolve;
-
- /// <summary>
- /// Registers the specified assembly and resolves the types in it when the AppDomain requests for it.
- /// </summary>
- /// <param name="assemblyFilePath">The path to the assemly to load in the LoadFrom context.</param>
- /// <remarks>This method does not load the assembly immediately, but lazily until someone requests a <see cref="Type"/>
- /// declared in the assembly.</remarks>
- public void LoadAssemblyFrom(string assemblyFilePath)
- {
- if (!this.handlesAssemblyResolve)
- {
- AppDomain.CurrentDomain.AssemblyResolve += this.CurrentDomain_AssemblyResolve;
- this.handlesAssemblyResolve = true;
- }
-
- Uri assemblyUri = GetFileUri(assemblyFilePath);
-
- if (assemblyUri == null)
- {
- throw new ArgumentException(Resources.InvalidArgumentAssemblyUri, "assemblyFilePath");
- }
-
- if (!File.Exists(assemblyUri.LocalPath))
- {
- throw new FileNotFoundException();
- }
-
- AssemblyName assemblyName = AssemblyName.GetAssemblyName(assemblyUri.LocalPath);
- AssemblyInfo assemblyInfo = this.registeredAssemblies.FirstOrDefault(a => assemblyName == a.AssemblyName);
-
- if (assemblyInfo != null)
- {
- return;
- }
-
- assemblyInfo = new AssemblyInfo() { AssemblyName = assemblyName, AssemblyUri = assemblyUri };
- this.registeredAssemblies.Add(assemblyInfo);
- }
-
- private static Uri GetFileUri(string filePath)
- {
- if (String.IsNullOrEmpty(filePath))
- {
- return null;
- }
-
- Uri uri;
- if (!Uri.TryCreate(filePath, UriKind.Absolute, out uri))
- {
- return null;
- }
-
- if (!uri.IsFile)
- {
- return null;
- }
-
- return uri;
- }
-
- [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Reliability", "CA2001:AvoidCallingProblematicMethods", MessageId = "System.Reflection.Assembly.LoadFrom")]
- private Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
- {
- AssemblyName assemblyName = new AssemblyName(args.Name);
-
- AssemblyInfo assemblyInfo = this.registeredAssemblies.FirstOrDefault(a => AssemblyName.ReferenceMatchesDefinition(assemblyName, a.AssemblyName));
-
- if (assemblyInfo != null)
- {
- if (assemblyInfo.Assembly == null)
- {
- assemblyInfo.Assembly = Assembly.LoadFrom(assemblyInfo.AssemblyUri.LocalPath);
- }
-
- return assemblyInfo.Assembly;
- }
-
- return null;
- }
-
- private class AssemblyInfo
- {
- public AssemblyName AssemblyName { get; set; }
-
- public Uri AssemblyUri { get; set; }
-
- public Assembly Assembly { get; set; }
- }
-
- #region Implementation of IDisposable
-
- /// <summary>
- /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
- /// </summary>
- /// <remarks>Calls <see cref="Dispose(bool)"/></remarks>.
- /// <filterpriority>2</filterpriority>
- public void Dispose()
- {
- this.Dispose(true);
- GC.SuppressFinalize(this);
- }
-
- /// <summary>
- /// Disposes the associated <see cref="AssemblyResolver"/>.
- /// </summary>
- /// <param name="disposing">When <see langword="true"/>, it is being called from the Dispose method.</param>
- protected virtual void Dispose(bool disposing)
- {
- if (this.handlesAssemblyResolve)
- {
- AppDomain.CurrentDomain.AssemblyResolve -= this.CurrentDomain_AssemblyResolve;
- this.handlesAssemblyResolve = false;
- }
- }
-
- #endregion
- }
- }