exceptiontree.cs

Microsoft.NET.框架程序设计修订版中的书中源码

/******************************************************************************
Module:  ExceptionTree.cs
Notices: Copyright (c) 2002 Jeffrey Richter
******************************************************************************/


using System;
using System.Text;
using System.Reflection;
using System.Collections;


///////////////////////////////////////////////////////////////////////////////


class App {
   static void Main() {
      // Explicitly load the assemblies that we want to relfect over
      LoadAssemblies();

      // Initialize our counters and our exception type list
      Int32 totalTypes = 0, totalExceptionTypes = 0;
      ArrayList exceptionTree = new ArrayList();

      // Iterate through all assemblies loaded in this AppDomain
      foreach (Assembly a in AppDomain.CurrentDomain.GetAssemblies()) {

         // Iterate through all types defined in this assembly
         foreach (Type t in a.GetTypes()) { 

            totalTypes++;

            // Ignore type if not a public class
            if (!t.IsClass || !t.IsPublic) continue;

            // Build a string of the type's derivation hierarchy
            StringBuilder typeHierarchy = 
               new StringBuilder(t.FullName, 5000);

            // Assume that the type is not an Exception-derived type
            Boolean derivedFromException = false;

            // See if System.Exception is a base type of this type
            Type baseType = t.BaseType;
            while ((baseType != null) && !derivedFromException) {
               // Append the base type to the end of the string
               typeHierarchy.Append("-" + baseType);

               derivedFromException = 
                  (baseType == typeof(System.Exception));
               baseType = baseType.BaseType;
            }

            // No more bases and not Exception-derived, try next type
            if (!derivedFromException) continue;

            // We found an Exception-derived type
            totalExceptionTypes++;

            // For this Exception-derived type, 
            // reverse the order of the types in the hierarchy
            String[] h = typeHierarchy.ToString().Split('-');
            Array.Reverse(h);

            // Build a new string with the hierarchy in order 
            // from Exception -> Exception-derived type 
            // Add the string to the list of Exception types
            exceptionTree.Add(String.Join("-", h, 1, h.Length - 1));
         }
      }

      // Sort the Exception types together in order of their hierarchy
      exceptionTree.Sort();

      // Display the Exception tree
      foreach (String s in exceptionTree) {
         // For this Exception types, split its base types apart
         String[] x = s.Split('-');

         // Indent based on the number of base types 
         // and then show the most-derived type
         Console.WriteLine(
            new String(' ', 3 * x.Length) + x[x.Length - 1]);
      }

      // Show final status of the types considerred
      Console.WriteLine("\n---> Of {0} types, {1} are " +
         "derived from System.Exception.", 
         totalTypes, totalExceptionTypes);

      Console.WriteLine("Press <Enter> to terminate this application.");
      Console.ReadLine();
   }


   static void LoadAssemblies() {
      String[] assemblies = {
         "System,                    PublicKeyToken={0}",
         "System.Data,               PublicKeyToken={0}",
         "System.Design,             PublicKeyToken={1}",
         "System.DirectoryServices,  PublicKeyToken={1}",
         "System.Drawing,            PublicKeyToken={1}",
         "System.Drawing.Design,     PublicKeyToken={1}",
         "System.EnterpriseServices, PublicKeyToken={1}",
         "System.Management,         PublicKeyToken={1}",
         "System.Messaging,          PublicKeyToken={1}",
         "System.Runtime.Remoting,   PublicKeyToken={0}",
         "System.Security,           PublicKeyToken={1}",
         "System.ServiceProcess,     PublicKeyToken={1}",
         "System.Web,                PublicKeyToken={1}",
         "System.Web.RegularExpressions, PublicKeyToken={1}",
         "System.Web.Services,       PublicKeyToken={1}",
         "System.Windows.Forms,      PublicKeyToken={0}",
         "System.Xml,                PublicKeyToken={0}",
      };

      String EcmaPublicKeyToken = "b77a5c561934e089";
      String MSPublicKeyToken   = "b03f5f7f11d50a3a";

      // Get the version of the assembly containing System.Object
      // We'll assume the same version for all the other assemblies
      Version version = 
         typeof(System.Object).Assembly.GetName().Version;

      // Explicitly load the assemblies that we want to reflect over
      foreach (String a in assemblies) {
         String AssemblyIdentity = 
            String.Format(a, EcmaPublicKeyToken, MSPublicKeyToken) + 
            ", Culture=neutral, Version=" + version;

         Assembly.Load(AssemblyIdentity);
      }
   }
}


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