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Char::ConvertFromUtf32 Method (Int32)

 

Converts the specified Unicode code point into a UTF-16 encoded string.

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

public:
static String^ ConvertFromUtf32(
	int utf32
)

Parameters

utf32
Type: System::Int32

A 21-bit Unicode code point.

Return Value

Type: System::String^

A string consisting of one Char object or a surrogate pair of Char objects equivalent to the code point specified by the utf32 parameter.

Exception Condition
ArgumentOutOfRangeException

utf32 is not a valid 21-bit Unicode code point ranging from U+0 through U+10FFFF, excluding the surrogate pair range from U+D800 through U+DFFF.

Use this method to convert a 21-bit Unicode code point to a UTF-16 encoded string before testing the string with methods such as IsLowSurrogate(Char) and IsHighSurrogate(Char).

A valid code point outside the Basic Multilingual Plane (BMP) always yields a valid surrogate pair. However, a valid code point within the BMP might not yield a valid result according to the Unicode standard because no linguistic processing is used in the conversion. For that reason, use the System.Text::UTF32Encoding class to convert bulk UTF-32 data into bulk UTF-16 data.

The following code example demonstrates the ConvertToUtf32 and ConvertFromUtf32 methods.

// This example demonstrates the Char.ConvertFromUtf32() method
//                           and Char.ConvertToUtf32() overloads.
using namespace System;
void Show( String^ s )
{
//   Console::Write( "0x{0:X}, 0x{1:X}", (int)s->get_Chars( 0 ), (int)s->get_Chars( 1 ) );
   Console::Write( "0x{0:X}, 0x{1:X}", (int)s[ 0 ], (int)s[ 1 ] );
}

int main()
{
   int music = 0x1D161; //U+1D161 = MUSICAL SYMBOL SIXTEENTH NOTE

   String^ s1;
   String^ comment1a = "Create a UTF-16 encoded string from a code point.";
   String^ comment1b = "Create a code point from a surrogate pair at a certain position in a string.";
   String^ comment1c = "Create a code point from a high surrogate and a low surrogate code point.";

   // -------------------------------------------------------------------
   //  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( comment1a );
   s1 = Char::ConvertFromUtf32( music );
   Console::Write( "    1a) 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( comment1b );
   music = Char::ConvertToUtf32( s1, 0 );
   Console::Write( "    1b) " );
   Show( s1 );
   Console::WriteLine( " => 0x{0:X}", music );

   //  Convert the high and low characters in the surrogate pair into a code point.
   Console::WriteLine( comment1c );
   music = Char::ConvertToUtf32( s1[ 0 ], s1[ 1 ] );
   Console::Write( "    1c) " );
   Show( s1 );
   Console::WriteLine( " => 0x{0:X}", music );
}

/*
This example produces the following results:

Create a UTF-16 encoded string from a code point.
    1a) 0x1D161 => 0xD834, 0xDD61
Create a code point from a surrogate pair at a certain position in a string.
    1b) 0xD834, 0xDD61 => 0x1D161
Create a code point from a high surrogate and a low surrogate code point.
    1c) 0xD834, 0xDD61 => 0x1D161

*/

Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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