SortedList Constructor (IDictionary, IComparer)

 
System_CAPS_noteNote

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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-

null to use the IComparable implementation of each key.

Exception Condition
ArgumentNullException

d is null.

InvalidCastException

comparer is null, 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 null, 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 System;
using System.Collections;
using System.Globalization;

public class SamplesSortedList
{

    public static void Main()
    {

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

        // Create a SortedList using the default comparer.
        SortedList mySL1 = new 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 = new SortedList(myHT, new 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 = new CultureInfo("tr-TR");
        SortedList mySL3 = new SortedList(myHT, new 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
        // StringComparer.InvariantCultureIgnoreCase value.
        SortedList mySL4 = new SortedList(
            myHT, StringComparer.InvariantCultureIgnoreCase);

        Console.WriteLine("mySL4 (InvariantCultureIgnoreCase):");
        try
        {
            mySL4.Add("first", "Ola!");
        }
        catch (ArgumentException e)
        {
            Console.WriteLine(e);
        }
        PrintKeysAndValues(mySL4);

    }

    public static 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();
    }
}


/* 
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 : !

*/

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
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