mcs/class/System.ComponentModel.Composition/src/ComponentModel/System/ComponentModel/Composition/Primitives/ExportedDelegate.cs

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Diagnostics.CodeAnalysis;\r
   6 using System.Reflection;\r
   7 using Microsoft.Internal;\r
   8 \r
   9 namespace System.ComponentModel.Composition.Primitives\r
  10 {\r
  11     [SuppressMessage("Microsoft.Naming", "CA1711:IdentifiersShouldNotHaveIncorrectSuffix")]\r
  12     public class ExportedDelegate\r
  13     {\r
  14         private object _instance;\r
  15         private MethodInfo _method;\r
  16 \r
  17         protected ExportedDelegate() { }\r
  18 #if !SILVERLIGHT\r
  19         [System.Security.SecurityCritical]\r
  20 #endif\r
  21         public ExportedDelegate(object instance, MethodInfo method)\r
  22         {\r
  23             Requires.NotNull(method, "method");\r
  24 \r
  25             this._instance = instance;\r
  26             this._method = method;\r
  27         }\r
  28 \r
  29         public virtual Delegate CreateDelegate(Type delegateType) \r
  30         {\r
  31             Requires.NotNull(delegateType, "delegateType");\r
  32 \r
  33             if (delegateType == typeof(Delegate) || delegateType == typeof(MulticastDelegate))\r
  34             {\r
  35                 Type funcOrAction = ConvertMethodInfoToFuncOrActionType(this._method);\r
  36 \r
  37                 if (funcOrAction != null)\r
  38                 {\r
  39                     delegateType = funcOrAction;\r
  40                 }\r
  41                 else\r
  42                 {\r
  43                     return null;\r
  44                 }\r
  45             }\r
  46 \r
  47             return Delegate.CreateDelegate(delegateType, this._instance, this._method, false);\r
  48         }\r
  49 \r
  50         private static Type[] _funcTypes = \r
  51         { \r
  52             typeof(Func<>), typeof(Func<,>), typeof(Func<,,>), typeof(Func<,,,>), typeof(Func<,,,,>) \r
  53 #if CLR40 && !SILVERLIGHT\r
  54             , typeof(Func<,,,,,>), typeof(Func<,,,,,,>), typeof(Func<,,,,,,,>), typeof(Func<,,,,,,,,>)\r
  55 #endif \r
  56         };\r
  57 \r
  58         private static Type[] _actionTypes = \r
  59         { \r
  60             typeof(Action), typeof(Action<>), typeof(Action<,>), typeof(Action<,,>), typeof(Action<,,,>) \r
  61 #if CLR40 && !SILVERLIGHT\r
  62             , typeof(Action<,,,,>), typeof(Action<,,,,,>), typeof(Action<,,,,,,>), typeof(Action<,,,,,,,>)\r
  63 #endif\r
  64         };\r
  65 \r
  66         private static Type ConvertMethodInfoToFuncOrActionType(MethodInfo method)\r
  67         {\r
  68             ParameterInfo[] parameters = method.GetParameters();\r
  69 \r
  70             bool isVoid = method.ReturnType == typeof(void);\r
  71             Type[] typeArray = isVoid ? _actionTypes : _funcTypes;\r
  72 \r
  73             if (parameters.Length >= typeArray.Length)\r
  74             {\r
  75                 return null;\r
  76             }\r
  77 \r
  78             Type[] genericArgTypes = new Type[parameters.Length + (isVoid ? 0 : 1)];\r
  79 \r
  80             for (int i = 0; i < parameters.Length; i++)\r
  81             {\r
  82                 genericArgTypes[i] = parameters[i].ParameterType;\r
  83             }\r
  84 \r
  85             if (!isVoid)\r
  86             {\r
  87                 genericArgTypes[parameters.Length] = method.ReturnType;\r
  88             }\r
  89 \r
  90             Type delegateType = typeArray[parameters.Length].IsGenericType ?\r
  91                 typeArray[parameters.Length].MakeGenericType(genericArgTypes) :\r
  92                 typeArray[parameters.Length];\r
  93 \r
  94             return delegateType;\r
  95         }\r
  96     }\r
  97 }\r