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Char.ConvertToUtf32 Method (String, Int32)

Note: This method is new in the .NET Framework version 2.0.

Converts the value of a UTF-16 encoded character or surrogate pair at a specified position in a string into a Unicode code point.

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

public static int ConvertToUtf32 (
	string s,
	int index
)
public static int ConvertToUtf32 (
	String s, 
	int index
)
public static function ConvertToUtf32 (
	s : String, 
	index : int
) : int

Parameters

s

A string that contains a character or surrogate pair.

index

The index position of the character or surrogate pair in s.

Return Value

The 21-bit Unicode code point represented by the character or surrogate pair at the position in the s parameter specified by the index parameter.
Exception typeCondition

ArgumentNullException

s is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

index is not a position within s.

ArgumentException

The specified index position contains a surrogate pair, and either the first character in the pair is not a valid high surrogate or the second character in the pair is not a valid low surrogate.

Use this method to convert a character or surrogate pair into a 21-bit Unicode code point. To convert UTF-16 data into UTF-32 data, use the System.Text.UTF32Encoding class.

The following code example demonstrates the ConvertToUtf32 and ConvertFromUtf32 methods.

// This example demonstrates the Char.ConvertFromUtf32() method
//                           and Char.ConvertToUtf32() overloads.
using System;

class Sample 
{
    public static void Main() 
    {
    int letterA = 0x0041;  //U+00041 = LATIN CAPITAL LETTER A
    int music   = 0x1D161; //U+1D161 = MUSICAL SYMBOL SIXTEENTH NOTE
    string s1;
    string comment   = "Create a UTF-16 encoded string from a code point.";
    string comment1b = "Create a code point from a UTF-16 encoded string.";
    string comment2b = "Create a code point from a surrogate pair at a certain position in a string.";
    string comment2c = "Create a code point from a high surrogate and a low surrogate character.";

//  Convert code point U+0041 to UTF-16. The UTF-16 equivalent of 
//  U+0041 is a Char with hexadecimal value 0041.

    Console.WriteLine(comment);
    s1 = Char.ConvertFromUtf32(letterA);
    Console.Write("    1a) 0x{0:X} => ", letterA);
    Show(s1);
    Console.WriteLine();

//  Convert the lone UTF-16 character to a code point.

    Console.WriteLine(comment1b);
    letterA = Char.ConvertToUtf32(s1, 0);
    Console.Write("    1b) ");
    Show(s1);
    Console.WriteLine(" => 0x{0:X}", letterA);
    Console.WriteLine();

// -------------------------------------------------------------------

//  Convert the code point U+1D161 to UTF-16. The UTF-16 equivalent of 
//  U+1D161 is a surrogate pair with hexadecimal values D834 and DD61.

    Console.WriteLine(comment);
    s1 = Char.ConvertFromUtf32(music);
    Console.Write("    2a) 0x{0:X} => ", music);
    Show(s1);
    Console.WriteLine();

//  Convert the surrogate pair in the string at index position 
//  zero to a code point.

    Console.WriteLine(comment2b);
    music = Char.ConvertToUtf32(s1, 0);
    Console.Write("    2b) ");
    Show(s1);
    Console.WriteLine(" => 0x{0:X}", music);

//  Convert the high and low characters in the surrogate pair into a code point.

    Console.WriteLine(comment2c);
    music = Char.ConvertToUtf32(s1[0], s1[1]);
    Console.Write("    2c) ");
    Show(s1);
    Console.WriteLine(" => 0x{0:X}", music);
    }

    private static void Show(string s)
    {
    for (int x = 0; x < s.Length; x++)
        {
        Console.Write("0x{0:X}{1}", 
                       (int)s[x], 
                       ((x == s.Length-1)? String.Empty : ", "));
        }
    }
}
/*
This example produces the following results:

Create a UTF-16 encoded string from a code point.
    1a) 0x41 => 0x41
Create a code point from a UTF-16 encoded string.
    1b) 0x41 => 0x41

Create a UTF-16 encoded string from a code point.
    2a) 0x1D161 => 0xD834, 0xDD61
Create a code point from a surrogate pair at a certain position in a string.
    2b) 0xD834, 0xDD61 => 0x1D161
Create a code point from a high surrogate and a low surrogate character.
    2c) 0xD834, 0xDD61 => 0x1D161

*/

// This example demonstrates the Char.ConvertFromUtf32() method
// and Char.ConvertToUtf32() overloads.
import System.*;

class Sample
{
    public static void main(String[] args)
    {
        int letterA = 0x41; //U+00041 = LATIN CAPITAL LETTER A
        int music = 0x1D161; //U+1D161 = MUSICAL SYMBOL SIXTEENTH NOTE
        String s1;
        String comment = "Create a UTF-16 encoded string from a code point.";
        String comment1B = "Create a code point from a UTF-16 encoded string.";
        String comment2B = "Create a code point from a surrogate pair at a "
            + " certain position in a string.";
        String comment2C = "Create a code point from a high surrogate and a"
            + " low surrogate character.";
        //  Convert code point U+0041 to UTF-16. The UTF-16 equivalent of 
        //  U+0041 is a Char with hexadecimal value 0041.
        Console.WriteLine(comment);
        s1 = Char.ConvertFromUtf32(letterA);
        Console.Write("    1a) 0x{0:X} => ", (Int32)letterA);
        Show(s1);
        Console.WriteLine();
        //  Convert the lone UTF-16 character to a code point.
        Console.WriteLine(comment1B);
        letterA = Char.ConvertToUtf32(s1, 0);
        Console.Write("    1b) ");
        Show(s1);
        Console.WriteLine(" => 0x{0:X}", (Int32)letterA);
        Console.WriteLine();
        // -------------------------------------------------------------------
        //  Convert the code point U+1D161 to UTF-16. The UTF-16 equivalent of 
        //  U+1D161 is a surrogate pair with hexadecimal values D834 and DD61.
        Console.WriteLine(comment);
        s1 = Char.ConvertFromUtf32(music);
        Console.Write("    2a) 0x{0:X} => ", (Int32)music);
        Show(s1);
        Console.WriteLine();
        //  Convert the surrogate pair in the string at index position 
        //  zero to a code point.
        Console.WriteLine(comment2B);
        music = Char.ConvertToUtf32(s1, 0);
        Console.Write("    2b) ");
        Show(s1);
        Console.WriteLine(" => 0x{0:X}", (Int32)music);
        //  Convert the high and low characters in the surrogate pair into a
        //  code point.
        Console.WriteLine(comment2C);
        music = Char.ConvertToUtf32(s1.get_Chars(0), s1.get_Chars(1));
        Console.Write("    2c) ");
        Show(s1);
        Console.WriteLine(" => 0x{0:X}", (Int32)music);
    } //main

    private static void Show(String s)
    {
        for (int x = 0; x < s.get_Length(); x++) {
            Console.Write("0x{0:X}{1}", (Int32)(s.get_Chars(x)),
                (x == s.get_Length() - 1) ? "" : ", ");
        }
    } //Show
} //Sample

/*
This example produces the following results:

Create a UTF-16 encoded string from a code point.
    1a) 0x41 => 0x41
Create a code point from a UTF-16 encoded string.
    1b) 0x41 => 0x41

Create a UTF-16 encoded string from a code point.
    2a) 0x1D161 => 0xD834, 0xDD61
Create a code point from a surrogate pair at a certain position in a string.
    2b) 0xD834, 0xDD61 => 0x1D161
Create a code point from a high surrogate and a low surrogate character.
    2c) 0xD834, 0xDD61 => 0x1D161

*/

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0
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