Char.ConvertFromUtf32(Int32) Methode
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Converteert het opgegeven Unicode-codepunt naar een UTF-16-gecodeerde tekenreeks.
public:
static System::String ^ ConvertFromUtf32(int utf32);public static string ConvertFromUtf32(int utf32);static member ConvertFromUtf32 : int -> stringPublic Shared Function ConvertFromUtf32 (utf32 As Integer) As StringParameters
- utf32
- Int32
Een 21-bits Unicode-codepunt.
Retouren
Een tekenreeks die bestaat uit één Char object of een surrogaatpaar van Char objecten die gelijk zijn aan het codepunt dat is opgegeven door de utf32 parameter.
Uitzonderingen
utf32 is geen geldig 21-bits Unicode-codepunt, variërend van U+0 tot en met U+10FFFF, met uitzondering van het surrogaatpaarbereik van U+D800 tot en met U+DFFF.
Voorbeelden
In het volgende codevoorbeeld ziet u de ConvertToUtf32 en ConvertFromUtf32 methoden.
// 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 code point.";
// 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 code point.
2c) 0xD834, 0xDD61 => 0x1D161
*/
open System
let show (s: string) =
for x = 0 to s.Length - 1 do
printf $"""0x{int s[x]:X}{if x = s.Length - 1 then String.Empty else ", "}"""
[<EntryPoint>]
let main _ =
let letterA = 0x0041 //U+00041 = LATIN CAPITAL LETTER A
let music = 0x1D161 //U+1D161 = MUSICAL SYMBOL SIXTEENTH NOTE
let comment = "Create a UTF-16 encoded string from a code point."
let comment1b = "Create a code point from a UTF-16 encoded string."
let comment2b = "Create a code point from a surrogate pair at a certain position in a string."
let comment2c = "Create a code point from a high surrogate and a low surrogate code point."
// Convert code point U+0041 to UTF-16. The UTF-16 equivalent of
// U+0041 is a Char with hexadecimal value 0041.
printfn $"{comment}"
let s1 = Char.ConvertFromUtf32 letterA
printf $" 1a) 0x{letterA:X} => "
show s1
printfn ""
// Convert the lone UTF-16 character to a code point.
printfn $"{comment1b}"
let letterA = Char.ConvertToUtf32(s1, 0)
printf " 1b) "
show s1
printfn $" => 0x{letterA:X}"
printfn ""
// -------------------------------------------------------------------
// 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.
printfn $"{comment}"
let s1 = Char.ConvertFromUtf32 music
printf $" 2a) 0x{music:X} => "
show s1
printfn ""
// Convert the surrogate pair in the string at index position
// zero to a code point.
printfn $"{comment2b}"
let music = Char.ConvertToUtf32(s1, 0)
printf " 2b) "
show s1
printfn $" => 0x{music:X}"
// Convert the high and low characters in the surrogate pair into a code point.
printfn $"{comment2c}"
let music = Char.ConvertToUtf32(s1[0], s1[1])
printf " 2c) "
show s1
printfn $" => 0x{music:X}"
0
// 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 code point.
// 2c) 0xD834, 0xDD61 => 0x1D161
Class Sample
Public Shared Sub Main()
Dim letterA As Integer = &H41 'U+00041 = LATIN CAPITAL LETTER A
Dim music As Integer = &H1D161 'U+1D161 = MUSICAL SYMBOL SIXTEENTH NOTE
Dim s1 As String
Dim comment As String = "Create a UTF-16 encoded string from a code point."
Dim comment1b As String = "Create a code point from a UTF-16 encoded string."
Dim comment2b As String = "Create a code point from a surrogate pair at a certain position in a string."
Dim comment2c As String = "Create a code point from a high surrogate and a low surrogate code point."
' 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.Chars(0), s1.Chars(1))
Console.Write(" 2c) ")
Show(s1)
Console.WriteLine(" => 0x{0:X}", music)
End Sub
Private Shared Sub Show(s As String)
Dim x As Integer
If s.Length = 0 Then Exit Sub
For x = 0 To s.Length - 1
Console.Write("0x{0:X}{1}", _
AscW(s.Chars(x)), _
IIf(x = s.Length - 1, [String].Empty, ", "))
Next
End Sub
End Class
'
'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 code point.
' 2c) 0xD834, 0xDD61 => 0x1D161
'
Opmerkingen
Gebruik deze methode om een 21-bits Unicode-codepunt te converteren naar een UTF-16 gecodeerde tekenreeks voordat u de tekenreeks test met methoden zoals IsLowSurrogate(Char) en IsHighSurrogate(Char).
Een geldig codepunt buiten het BMP (Basic Multilingual Plane) levert altijd een geldig surrogaatpaar op. Een geldig codepunt binnen het BMP levert echter mogelijk geen geldig resultaat op volgens de Unicode-standaard omdat er geen taalkundige verwerking wordt gebruikt in de conversie. Gebruik daarom de System.Text.UTF32Encoding klasse om bulk-UTF-32-gegevens te converteren naar bulk-UTF-16-gegevens.