Char.ConvertToUtf32 方法

参考

定义

命名空间:: System

程序集:: System.Runtime.dll

程序集:: netstandard.dll

程序集:: mscorlib.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

将 UTF-16 编码的代理项对的值转换为 Unicode 码位。

重载

ConvertToUtf32(Char, Char)	将 UTF-16 编码的代理项对的值转换为 Unicode 码位。
ConvertToUtf32(String, Int32)	将字符串中指定位置的 UTF-16 编码字符或代理项对的值转换为 Unicode 码位。

示例

下面的代码示例演示了 ConvertToUtf32 和 ConvertFromUtf32 方法。

// 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

*/

// 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
'

ConvertToUtf32(Char, Char)

将 UTF-16 编码的代理项对的值转换为 Unicode 码位。

public:
 static int ConvertToUtf32(char highSurrogate, char lowSurrogate);

public static int ConvertToUtf32 (char highSurrogate, char lowSurrogate);

static member ConvertToUtf32 : char * char -> int

Public Shared Function ConvertToUtf32 (highSurrogate As Char, lowSurrogate As Char) As Integer

参数

highSurrogate: Char

高代理项代码单位（即代码单位从 U+D800 到 U+DBFF）。

lowSurrogate: Char

低代理项代码单位（即代码单位从 U+DC00 到 U+DFFF）。

Int32

highSurrogate 和 lowSurrogate 参数表示的 21 位 Unicode 码位。

例外

ArgumentOutOfRangeException

highSurrogate 不在 U + D800 到 U + DBFF 的范围内，或者 lowSurrogate 不在 U + DC00 到 U+DFFF 的范围内。

注解

使用此方法将代理项对转换为21位 Unicode 码位。若要将 UTF-16 数据转换为32数据，请使用 System.Text.UTF32Encoding 类。

通常，UTF-16 编码表示一个 Unicode 字符作为16位代码单元。但是，它还支持代理项对，这允许将单个抽象字符表示为 2 16 位代码单元。这两个 Char 对象的代码单位必须是从 u + D800 到 u + DBFF 的第一个 (高) 代理项和 u + DC00 到 u + DFFF 之间，第二个对象 (low) 代理项。仅 UTF-16 编码支持代理项对。此方法允许将 UTF-16 代理项对所表示的字符转换为使用 32 UTF-16 编码的字符。

另请参阅

适用于

ConvertToUtf32(String, Int32)

将字符串中指定位置的 UTF-16 编码字符或代理项对的值转换为 Unicode 码位。

public:
 static int ConvertToUtf32(System::String ^ s, int index);

public static int ConvertToUtf32 (string s, int index);

static member ConvertToUtf32 : string * int -> int

Public Shared Function ConvertToUtf32 (s As String, index As Integer) As Integer

参数

s: String

包含字符或代理项对的字符串。

index: Int32

字符或代理项对在 s 中的索引位置。

Int32

字符或代理项对表示的 21 位 Unicode 码位，该字符或代理项对在 s 参数中的位置由 index 参数指定。

例外

ArgumentNullException

s 上声明的默认值为 null。

ArgumentOutOfRangeException

index 不是 s 内的位置。

ArgumentException

指定的索引位置包含代理项对，且对中的第一个字符不是有效的高代理项或对中的第二个字符不是有效的低代理项。

注解

使用此方法将字符或代理项对转换为21位 Unicode 码位。若要将 UTF-16 数据转换为32数据，请使用 System.Text.UTF32Encoding 类。

另请参阅

适用于

通过

Char.ConvertToUtf32 方法

定义

重载

示例

ConvertToUtf32(Char, Char)

参数

返回

例外

注解

另请参阅

适用于

ConvertToUtf32(String, Int32)

参数

返回

例外

注解

另请参阅

适用于

其他资源