Export (0) Print
Expand All
1 out of 2 rated this helpful - Rate this topic

StringDictionary Class

Implements a hash table with the key and the value strongly typed to be strings rather than objects.

System::Object
  System.Collections.Specialized::StringDictionary

Namespace:  System.Collections.Specialized
Assembly:  System (in System.dll)
[SerializableAttribute]
public ref class StringDictionary : IEnumerable

The StringDictionary type exposes the following members.

  NameDescription
Public methodSupported by the XNA FrameworkStringDictionaryInitializes a new instance of the StringDictionary class.
Top
  NameDescription
Public propertySupported by the XNA FrameworkCountGets the number of key/value pairs in the StringDictionary.
Public propertySupported by the XNA FrameworkIsSynchronizedGets a value indicating whether access to the StringDictionary is synchronized (thread safe).
Public propertySupported by the XNA FrameworkItemGets or sets the value associated with the specified key.
Public propertySupported by the XNA FrameworkKeysGets a collection of keys in the StringDictionary.
Public propertySupported by the XNA FrameworkSyncRootGets an object that can be used to synchronize access to the StringDictionary.
Public propertySupported by the XNA FrameworkValuesGets a collection of values in the StringDictionary.
Top
  NameDescription
Public methodSupported by the XNA FrameworkAddAdds an entry with the specified key and value into the StringDictionary.
Public methodSupported by the XNA FrameworkClearRemoves all entries from the StringDictionary.
Public methodSupported by the XNA FrameworkContainsKeyDetermines if the StringDictionary contains a specific key.
Public methodSupported by the XNA FrameworkContainsValueDetermines if the StringDictionary contains a specific value.
Public methodSupported by the XNA FrameworkCopyToCopies the string dictionary values to a one-dimensional Array instance at the specified index.
Public methodSupported by the XNA FrameworkEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by the XNA FrameworkGetEnumeratorReturns an enumerator that iterates through the string dictionary.
Public methodSupported by the XNA FrameworkGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by the XNA FrameworkGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by the XNA FrameworkRemoveRemoves the entry with the specified key from the string dictionary.
Public methodSupported by the XNA FrameworkToStringReturns a string that represents the current object. (Inherited from Object.)
Top
  NameDescription
Public Extension MethodAsParallelEnables parallelization of a query. (Defined by ParallelEnumerable.)
Public Extension MethodAsQueryableConverts an IEnumerable to an IQueryable. (Defined by Queryable.)
Public Extension MethodSupported by the XNA FrameworkCast<TResult>Casts the elements of an IEnumerable to the specified type. (Defined by Enumerable.)
Public Extension MethodSupported by the XNA FrameworkOfType<TResult>Filters the elements of an IEnumerable based on a specified type. (Defined by Enumerable.)
Top

A key cannot be nullptr, but a value can.

The key is handled in a case-insensitive manner; it is translated to lowercase before it is used with the string dictionary.

In .NET Framework version 1.0, this class uses culture-sensitive string comparisons. However, in .NET Framework version 1.1 and later, this class uses CultureInfo::InvariantCulture when comparing strings. For more information about how culture affects comparisons and sorting, see Comparing and Sorting Data for a Specific Culture and Performing Culture-Insensitive String Operations.

The following code example demonstrates several of the properties and methods of StringDictionary.


#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintKeysAndValues2( StringDictionary^ myCol );
void PrintKeysAndValues3( StringDictionary^ myCol );

int main()
{
   // Creates and initializes a new StringDictionary.
   StringDictionary^ myCol = gcnew StringDictionary;
   myCol->Add( "red", "rojo" );
   myCol->Add( "green", "verde" );
   myCol->Add( "blue", "azul" );

   // Display the contents of the collection using the enumerator.
   Console::WriteLine( "Displays the elements using the IEnumerator:" );
   PrintKeysAndValues2( myCol );

   // Display the contents of the collection using the Keys, Values, Count, and Item properties.
   Console::WriteLine( "Displays the elements using the Keys, Values, Count, and Item properties:" );
   PrintKeysAndValues3( myCol );

   // Copies the StringDictionary to an array with DictionaryEntry elements.
   array<DictionaryEntry>^myArr = gcnew array<DictionaryEntry>(myCol->Count);
   myCol->CopyTo( myArr, 0 );

   // Displays the values in the array.
   Console::WriteLine( "Displays the elements in the array:" );
   Console::WriteLine( "   KEY        VALUE" );
   for ( int i = 0; i < myArr->Length; i++ )
      Console::WriteLine( "   {0,-10} {1}", myArr[ i ].Key, myArr[ i ].Value );
   Console::WriteLine();

   // Searches for a value.
   if ( myCol->ContainsValue( "amarillo" ) )
      Console::WriteLine( "The collection contains the value \"amarillo\"." );
   else
      Console::WriteLine( "The collection does not contain the value \"amarillo\"." );

   Console::WriteLine();

   // Searches for a key and deletes it.
   if ( myCol->ContainsKey( "green" ) )
      myCol->Remove( "green" );

   Console::WriteLine( "The collection contains the following elements after removing \"green\":" );
   PrintKeysAndValues2( myCol );

   // Clears the entire collection.
   myCol->Clear();
   Console::WriteLine( "The collection contains the following elements after it is cleared:" );
   PrintKeysAndValues2( myCol );
}

// Uses the enumerator. 
void PrintKeysAndValues2( StringDictionary^ myCol )
{
   IEnumerator^ myEnumerator = myCol->GetEnumerator();
   DictionaryEntry de;
   Console::WriteLine( "   KEY                       VALUE" );
   while ( myEnumerator->MoveNext() )
   {
      de =  *dynamic_cast<DictionaryEntry^>(myEnumerator->Current);
      Console::WriteLine( "   {0,-25} {1}", de.Key, de.Value );
   }

   Console::WriteLine();
}

// Uses the Keys, Values, Count, and Item properties.
void PrintKeysAndValues3( StringDictionary^ myCol )
{
   array<String^>^myKeys = gcnew array<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();
}

/*
This code produces the following output.

Displays the elements using the IEnumerator:
   KEY                       VALUE
   red                       rojo
   blue                      azul
   green                     verde

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     red                       rojo
   1     blue                      azul
   2     green                     verde

Displays the elements in the array:
   KEY        VALUE
   red        rojo
   blue       azul
   green      verde

The collection does not contain the value "amarillo".

The collection contains the following elements after removing "green":
   KEY                       VALUE
   red                       rojo
   blue                      azul

The collection contains the following elements after it is cleared:
   KEY                       VALUE

*/


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

This implementation does not provide a synchronized (thread safe) wrapper for a StringDictionary, but derived classes can create their own synchronized versions of the StringDictionary using the SyncRoot property.

Enumerating through a collection is intrinsically not a thread-safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2014 Microsoft. All rights reserved.