c# - 在运行时获取非泛型 IDictionary 的键和值类型

Question

我想知道如何在运行时获取非泛型 IDictionary 的键和值类型。

对于泛型IDictionary，我们可以使用反射获取泛型参数，已回答here .

但对于非泛型 IDictionary，例如 HybridDictionary，如何获取键和值类型？

编辑:我可能没有正确描述我的问题。对于非泛型 IDictionary，如果我有 HyBridDictionary，它声明为

HyBridDictionary dict = new HyBridDictionary();

dict.Add("foo" , 1);
dict.Add("bar", 2);

如何知道key的类型是string，value的类型是int？

Answer 1

来自msdn页面:

Msdn Link

 // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues1( IDictionary myCol )  {
      Console.WriteLine( "   KEY                       VALUE" );
      foreach ( DictionaryEntry de in myCol )
         Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
      Console.WriteLine();
   }

   // Uses the enumerator. 
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues2( IDictionary myCol )  {
      IDictionaryEnumerator myEnumerator = myCol.GetEnumerator();
      Console.WriteLine( "   KEY                       VALUE" );
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value );
      Console.WriteLine();
   }

   // Uses the Keys, Values, Count, and Item properties.
   public static void PrintKeysAndValues3( HybridDictionary myCol )  {
      String[] myKeys = new String[myCol.Count];
      myCol.Keys.CopyTo( myKeys, 0 );

      Console.WriteLine( "   INDEX KEY                       VALUE" );
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[i], myCol[myKeys[i]] );
      Console.WriteLine();
   }