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SortedList Constructor (IDictionary, IComparer)

Initializes a new instance of the SortedList class that contains elements copied from the specified dictionary, has the same initial capacity as the number of elements copied, and is sorted according to the specified IComparer interface.

Namespace:  System.Collections
Assembly:  mscorlib (in mscorlib.dll)

public:
SortedList(
	IDictionary^ d, 
	IComparer^ comparer
)

Parameters

d
Type: System.Collections::IDictionary

The IDictionary implementation to copy to a new SortedList object.

comparer
Type: System.Collections::IComparer

The IComparer implementation to use when comparing keys.

-or-

nullptr to use the IComparable implementation of each key.

ExceptionCondition
ArgumentNullException

d is nullptr.

InvalidCastException

comparer is nullptr, and one or more elements in d do not implement the IComparable interface.

The elements are sorted according to the specified IComparer implementation. If the comparer parameter is nullptr, the IComparable implementation of each key is used; therefore, each key must implement the IComparable interface to be capable of comparisons with every other key in the SortedList object.

A Hashtable object is an example of an IDictionary implementation that can be passed to this constructor. The new SortedList object contains a copy of the keys and values stored in the Hashtable.

The capacity of a SortedList object is the number of elements that the SortedList can hold. As elements are added to a SortedList, the capacity is automatically increased as required by reallocating the internal array.

If the size of the collection can be estimated, specifying the initial capacity eliminates the need to perform a number of resizing operations while adding elements to the SortedList object.

This constructor is an O(n) operation, where n is the number of elements in d.

The following code example creates collections using different SortedList constructors and demonstrates the differences in the behavior of the collections.



using namespace System;
using namespace System::Collections;
using namespace System::Globalization;
void PrintKeysAndValues( SortedList^ myList )
{
   Console::WriteLine( "        -KEY-   -VALUE-" );
   for ( int i = 0; i < myList->Count; i++ )
   {
      Console::WriteLine( "        {0,-6}: {1}", myList->GetKey( i ), myList->GetByIndex( i ) );

   }
   Console::WriteLine();
}

int main()
{

   // Create the dictionary.
   Hashtable^ myHT = gcnew Hashtable;
   myHT->Add( "FIRST", "Hello" );
   myHT->Add( "SECOND", "World" );
   myHT->Add( "THIRD", "!" );

   // Create a SortedList using the default comparer.
   SortedList^ mySL1 = gcnew SortedList( myHT );
   Console::WriteLine( "mySL1 (default):" );
   try
   {
      mySL1->Add( "first", "Ola!" );
   }
   catch ( ArgumentException^ e ) 
   {
      Console::WriteLine( e );
   }

   PrintKeysAndValues( mySL1 );

   // Create a SortedList using the specified case-insensitive comparer.
   SortedList^ mySL2 = gcnew SortedList( myHT,gcnew CaseInsensitiveComparer );
   Console::WriteLine( "mySL2 (case-insensitive comparer):" );
   try
   {
      mySL2->Add( "first", "Ola!" );
   }
   catch ( ArgumentException^ e ) 
   {
      Console::WriteLine( e );
   }

   PrintKeysAndValues( mySL2 );

    // Create a SortedList using the specified CaseInsensitiveComparer, 
    // which is based on the Turkish culture (tr-TR), where "I" is not
    // the uppercase version of "i".
   CultureInfo^ myCul = gcnew CultureInfo( "tr-TR" );
   SortedList^ mySL3 = gcnew SortedList( myHT, gcnew CaseInsensitiveComparer( myCul ) );
   Console::WriteLine( "mySL3 (case-insensitive comparer, Turkish culture):" );
   try
   {
      mySL3->Add( "first", "Ola!" );
   }
   catch ( ArgumentException^ e ) 
   {
      Console::WriteLine( e );
   }

   PrintKeysAndValues( mySL3 );

   // Create a SortedList using the ComparisonType.InvariantCultureIgnoreCase value.
   SortedList^ mySL4 = gcnew SortedList( myHT, StringComparer::InvariantCultureIgnoreCase );
   Console::WriteLine( "mySL4 (InvariantCultureIgnoreCase):" );
   try
   {
      mySL4->Add( "first", "Ola!" );
   }
   catch ( ArgumentException^ e ) 
   {
      Console::WriteLine( e );
   }

   PrintKeysAndValues( mySL4 );
}

/* 
This code produces the following output.  Results vary depending on the system's culture settings.

mySL1 (default):
        -KEY-   -VALUE-
        first : Ola!
        FIRST : Hello
        SECOND: World
        THIRD : !

mySL2 (case-insensitive comparer):
System.ArgumentException: Item has already been added.  Key in dictionary: 'FIRST'  Key being added: 'first'
   at System.Collections.SortedList.Add(Object key, Object value)
   at SamplesSortedList.Main()
        -KEY-   -VALUE-
        FIRST : Hello
        SECOND: World
        THIRD : !

mySL3 (case-insensitive comparer, Turkish culture):
        -KEY-   -VALUE-
        FIRST : Hello
        first : Ola!
        SECOND: World
        THIRD : !

mySL4 (InvariantCultureIgnoreCase):
System.ArgumentException: Item has already been added.  Key in dictionary: 'FIRST'  Key being added: 'first'
   at System.Collections.SortedList.Add(Object key, Object value)
   at SamplesSortedList.Main()
        -KEY-   -VALUE-
        FIRST : Hello
        SECOND: World
        THIRD : !

*/

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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