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BitConverter.ToSingle Méthode

Définition

Surcharges

ToSingle(ReadOnlySpan<Byte>)

Convertit une étendue d’octets en lecture seule en une valeur à virgule flottante simple précision.

ToSingle(Byte[], Int32)

Retourne un nombre à virgule flottante simple précision converti à partir de quatre octets à une position spécifiée dans un tableau d'octets.

ToSingle(ReadOnlySpan<Byte>)

Convertit une étendue d’octets en lecture seule en une valeur à virgule flottante simple précision.

public:
 static float ToSingle(ReadOnlySpan<System::Byte> value);
public static float ToSingle (ReadOnlySpan<byte> value);
static member ToSingle : ReadOnlySpan<byte> -> single
Public Shared Function ToSingle (value As ReadOnlySpan(Of Byte)) As Single

Paramètres

value
ReadOnlySpan<Byte>

Étendue en lecture seule contenant les octets à convertir.

Retours

Single

Valeur à virgule flottante simple précision représentant les octets convertis.

Exceptions

La longueur de value est inférieure à la longueur d’une valeur Single.

S’applique à

ToSingle(Byte[], Int32)

Retourne un nombre à virgule flottante simple précision converti à partir de quatre octets à une position spécifiée dans un tableau d'octets.

public:
 static float ToSingle(cli::array <System::Byte> ^ value, int startIndex);
public static float ToSingle (byte[] value, int startIndex);
static member ToSingle : byte[] * int -> single
Public Shared Function ToSingle (value As Byte(), startIndex As Integer) As Single

Paramètres

value
Byte[]

Tableau d'octets.

startIndex
Int32

Position de départ dans value.

Retours

Single

Nombre à virgule flottante simple précision composé de quatre octets, à partir de startIndex.

Exceptions

startIndex est supérieur ou égal à la longueur de value moins 3, et inférieur ou égal à la longueur de value moins 1.

value a la valeur null.

startIndex est inférieur à zéro ou supérieur à la longueur de value moins 1.

Exemples

L’exemple de code suivant convertit les éléments de Byte tableaux en Single valeurs avec la ToSingle méthode.

// Example of the BitConverter::ToSingle method.
using namespace System;

// Convert four byte array elements to a float and display it.
void BAToSingle( array<unsigned char>^bytes, int index )
{
   float value = BitConverter::ToSingle( bytes, index );
   Console::WriteLine( "{0,5}{1,17}{2,18:E7}", index, BitConverter::ToString( bytes, index, 4 ), value );
}


// Display a byte array, using multiple lines if necessary.
void WriteMultiLineByteArray( array<unsigned char>^bytes )
{
   const int rowSize = 20;
   int iter;
   Console::WriteLine( "initial unsigned char array" );
   Console::WriteLine( "---------------------------" );
   for ( iter = 0; iter < bytes->Length - rowSize; iter += rowSize )
   {
      Console::Write( BitConverter::ToString( bytes, iter, rowSize ) );
      Console::WriteLine( "-" );

   }
   Console::WriteLine( BitConverter::ToString( bytes, iter ) );
   Console::WriteLine();
}

int main()
{
   array<unsigned char>^byteArray = {0,0,0,0,128,63,0,0,112,65,0,255,127,71,0,0,128,59,0,0,128,47,73,70,131,5,75,6,158,63,77,6,158,63,80,6,158,63,30,55,190,121,255,255,127,255,255,127,127,1,0,0,0,192,255,0,0,128,255,0,0,128,127};
   Console::WriteLine( "This example of the BitConverter::ToSingle( unsigned "
   "char[ ], int ) \nmethod generates the following output. It "
   "converts elements of a \nbyte array to float values.\n" );
   WriteMultiLineByteArray( byteArray );
   Console::WriteLine( "{0,5}{1,17}{2,18:E7}", "index", "array elements", "float" );
   Console::WriteLine( "{0,5}{1,17}{2,18:E7}", "-----", "--------------", "-----" );
   
   // Convert byte array elements to float values.
   BAToSingle( byteArray, 0 );
   BAToSingle( byteArray, 2 );
   BAToSingle( byteArray, 6 );
   BAToSingle( byteArray, 10 );
   BAToSingle( byteArray, 14 );
   BAToSingle( byteArray, 18 );
   BAToSingle( byteArray, 22 );
   BAToSingle( byteArray, 26 );
   BAToSingle( byteArray, 30 );
   BAToSingle( byteArray, 34 );
   BAToSingle( byteArray, 38 );
   BAToSingle( byteArray, 42 );
   BAToSingle( byteArray, 45 );
   BAToSingle( byteArray, 49 );
   BAToSingle( byteArray, 51 );
   BAToSingle( byteArray, 55 );
   BAToSingle( byteArray, 59 );
}

/*
This example of the BitConverter::ToSingle( unsigned char[ ], int )
method generates the following output. It converts elements of a
byte array to float values.

initial unsigned char array
---------------------------
00-00-00-00-80-3F-00-00-70-41-00-FF-7F-47-00-00-80-3B-00-00-
80-2F-49-46-83-05-4B-06-9E-3F-4D-06-9E-3F-50-06-9E-3F-1E-37-
BE-79-FF-FF-7F-FF-FF-7F-7F-01-00-00-00-C0-FF-00-00-80-FF-00-
00-80-7F

index   array elements             float
-----   --------------             -----
    0      00-00-00-00    0.0000000E+000
    2      00-00-80-3F    1.0000000E+000
    6      00-00-70-41    1.5000000E+001
   10      00-FF-7F-47    6.5535000E+004
   14      00-00-80-3B    3.9062500E-003
   18      00-00-80-2F    2.3283064E-010
   22      49-46-83-05    1.2345000E-035
   26      4B-06-9E-3F    1.2345671E+000
   30      4D-06-9E-3F    1.2345673E+000
   34      50-06-9E-3F    1.2345676E+000
   38      1E-37-BE-79    1.2345679E+035
   42      FF-FF-7F-FF   -3.4028235E+038
   45      FF-FF-7F-7F    3.4028235E+038
   49      01-00-00-00    1.4012985E-045
   51      00-00-C0-FF               NaN
   55      00-00-80-FF         -Infinity
   59      00-00-80-7F          Infinity
*/
// Example of the BitConverter.ToSingle method.
using System;

class BytesToSingleDemo
{
    const string formatter = "{0,5}{1,17}{2,18:E7}";

    // Convert four byte array elements to a float and display it.
    public static void BAToSingle( byte[ ] bytes, int index )
    {
        float value = BitConverter.ToSingle( bytes, index );

        Console.WriteLine( formatter, index,
            BitConverter.ToString( bytes, index, 4 ), value );
    }

    // Display a byte array, using multiple lines if necessary.
    public static void WriteMultiLineByteArray( byte[ ] bytes )
    {
        const int rowSize = 20;
        int iter;

        Console.WriteLine( "initial byte array" );
        Console.WriteLine( "------------------" );

        for( iter = 0; iter < bytes.Length - rowSize; iter += rowSize )
        {
            Console.Write(
                BitConverter.ToString( bytes, iter, rowSize ) );
            Console.WriteLine( "-" );
        }

        Console.WriteLine( BitConverter.ToString( bytes, iter ) );
        Console.WriteLine( );
    }

    public static void Main( )
    {
        byte[ ] byteArray = {
              0,   0,   0,   0, 128,  63,   0,   0, 112,  65,
              0, 255, 127,  71,   0,   0, 128,  59,   0,   0,
            128,  47,  73,  70, 131,   5,  75,   6, 158,  63,
             77,   6, 158,  63,  80,   6, 158,  63,  30,  55,
            190, 121, 255, 255, 127, 255, 255, 127, 127,   1,
              0,   0,   0, 192, 255,   0,   0, 128, 255,   0,
              0, 128, 127 };

        Console.WriteLine(
            "This example of the BitConverter.ToSingle( byte( ), " +
            "int ) \nmethod generates the following output. It " +
            "converts elements \nof a byte array to float values.\n" );

        WriteMultiLineByteArray( byteArray );

        Console.WriteLine( formatter, "index", "array elements",
            "float" );
        Console.WriteLine( formatter, "-----", "--------------",
            "-----" );

        // Convert byte array elements to float values.
        BAToSingle( byteArray, 0 );
        BAToSingle( byteArray, 2 );
        BAToSingle( byteArray, 6 );
        BAToSingle( byteArray, 10 );
        BAToSingle( byteArray, 14 );
        BAToSingle( byteArray, 18 );
        BAToSingle( byteArray, 22 );
        BAToSingle( byteArray, 26 );
        BAToSingle( byteArray, 30 );
        BAToSingle( byteArray, 34 );
        BAToSingle( byteArray, 38 );
        BAToSingle( byteArray, 42 );
        BAToSingle( byteArray, 45 );
        BAToSingle( byteArray, 49 );
        BAToSingle( byteArray, 51 );
        BAToSingle( byteArray, 55 );
        BAToSingle( byteArray, 59 );
    }
}

/*
This example of the BitConverter.ToSingle( byte( ), int )
method generates the following output. It converts elements
of a byte array to float values.

initial byte array
------------------
00-00-00-00-80-3F-00-00-70-41-00-FF-7F-47-00-00-80-3B-00-00-
80-2F-49-46-83-05-4B-06-9E-3F-4D-06-9E-3F-50-06-9E-3F-1E-37-
BE-79-FF-FF-7F-FF-FF-7F-7F-01-00-00-00-C0-FF-00-00-80-FF-00-
00-80-7F

index   array elements             float
-----   --------------             -----
    0      00-00-00-00    0.0000000E+000
    2      00-00-80-3F    1.0000000E+000
    6      00-00-70-41    1.5000000E+001
   10      00-FF-7F-47    6.5535000E+004
   14      00-00-80-3B    3.9062500E-003
   18      00-00-80-2F    2.3283064E-010
   22      49-46-83-05    1.2345000E-035
   26      4B-06-9E-3F    1.2345671E+000
   30      4D-06-9E-3F    1.2345673E+000
   34      50-06-9E-3F    1.2345676E+000
   38      1E-37-BE-79    1.2345679E+035
   42      FF-FF-7F-FF   -3.4028235E+038
   45      FF-FF-7F-7F    3.4028235E+038
   49      01-00-00-00    1.4012985E-045
   51      00-00-C0-FF               NaN
   55      00-00-80-FF         -Infinity
   59      00-00-80-7F          Infinity
*/
open System

let print obj1 obj2 obj3 = printfn $"{obj1,5}{obj2,17}{obj3,18:E7}"

// Convert four byte array elements to a float and display it.
let BAToSingle bytes index =
    let value = BitConverter.ToSingle(bytes, index)

    print index (BitConverter.ToString(bytes, index, 4)) value

// Display a byte array, using multiple lines if necessary.
let writeMultiLineByteArray (bytes: byte []) =
    let rowSize = 20

    printfn "initial byte array"
    printfn "------------------"

    let mutable iter = 0
    for i in 0 .. rowSize .. (bytes.Length - rowSize - 1) do
        printfn $"{BitConverter.ToString(bytes, iter, rowSize)}-"
        iter <- i

    printfn $"{BitConverter.ToString(bytes, iter + rowSize)}\n"

let byteArray =
    [| 0uy; 0uy; 0uy; 0uy; 128uy; 63uy; 0uy; 0uy; 112uy; 65uy
       0uy; 255uy; 127uy; 71uy; 0uy; 0uy; 128uy; 59uy; 0uy; 0uy
       128uy; 47uy; 73uy; 70uy; 131uy; 5uy; 75uy; 6uy; 158uy; 63uy
       77uy; 6uy; 158uy; 63uy; 80uy; 6uy; 158uy; 63uy; 30uy; 55uy
       190uy; 121uy; 255uy; 255uy; 127uy; 255uy; 255uy; 127uy; 127uy; 1uy
       0uy; 0uy; 0uy; 192uy; 255uy; 0uy; 0uy; 128uy; 255uy; 0uy
       0uy; 128uy; 127uy |]

printfn "This example of the BitConverter.ToSingle(byte [], int) \nmethod generates the following output. It converts elements \nof a byte array to float values.\n"

writeMultiLineByteArray byteArray

print "index" "array elements" "float"
print "-----" "--------------" "-----"

// Convert byte array elements to float values.
BAToSingle byteArray 0 
BAToSingle byteArray 2 
BAToSingle byteArray 6 
BAToSingle byteArray 10 
BAToSingle byteArray 14 
BAToSingle byteArray 18 
BAToSingle byteArray 22 
BAToSingle byteArray 26 
BAToSingle byteArray 30 
BAToSingle byteArray 34 
BAToSingle byteArray 38 
BAToSingle byteArray 42 
BAToSingle byteArray 45 
BAToSingle byteArray 49 
BAToSingle byteArray 51 
BAToSingle byteArray 55 
BAToSingle byteArray 59 


// This example of the BitConverter.ToSingle( byte( ), int )
// method generates the following output. It converts elements
// of a byte array to float values.
//
// initial byte array
// ------------------
// 00-00-00-00-80-3F-00-00-70-41-00-FF-7F-47-00-00-80-3B-00-00-
// 00-00-00-00-80-3F-00-00-70-41-00-FF-7F-47-00-00-80-3B-00-00-
// 80-2F-49-46-83-05-4B-06-9E-3F-4D-06-9E-3F-50-06-9E-3F-1E-37-
// 00-80-7F
//
// index   array elements             float
// -----   --------------             -----
//     0      00-00-00-00    0.0000000E+000
//     2      00-00-80-3F    1.0000000E+000
//     6      00-00-70-41    1.5000000E+001
//    10      00-FF-7F-47    6.5535000E+004
//    14      00-00-80-3B    3.9062500E-003
//    18      00-00-80-2F    2.3283064E-010
//    22      49-46-83-05    1.2345000E-035
//    26      4B-06-9E-3F    1.2345671E+000
//    30      4D-06-9E-3F    1.2345673E+000
//    34      50-06-9E-3F    1.2345676E+000
//    38      1E-37-BE-79    1.2345679E+035
//    42      FF-FF-7F-FF   -3.4028235E+038
//    45      FF-FF-7F-7F    3.4028235E+038
//    49      01-00-00-00    1.4012985E-045
//    51      00-00-C0-FF               NaN
//    55      00-00-80-FF                -∞
//    59      00-00-80-7F                 ∞
' Example of the BitConverter.ToSingle method.
Module BytesToSingleDemo

    Const formatter As String = "{0,5}{1,17}{2,18:E7}"
 
    ' Convert four Byte array elements to a Single and display it.
    Sub BAToSingle( bytes( ) As Byte, index As Integer )

        Dim value As Single = BitConverter.ToSingle( bytes, index )

        Console.WriteLine( formatter, index, _
            BitConverter.ToString( bytes, index, 4 ), value )
    End Sub 

    ' Display a Byte array, using multiple lines if necessary.
    Sub WriteMultiLineByteArray( bytes( ) As Byte )
       
        Const rowSize As Integer = 20 
        Dim iter As Integer

        Console.WriteLine( "initial Byte array" )
        Console.WriteLine( "------------------" )

        For iter = 0 To bytes.Length - rowSize - 1 Step rowSize
            Console.Write( _
                BitConverter.ToString( bytes, iter, rowSize ) )
            Console.WriteLine( "-" )
        Next iter

        Console.WriteLine( BitConverter.ToString( bytes, iter ) )
        Console.WriteLine( )
    End Sub

    Sub Main( )
        Dim byteArray as Byte( ) = { _
              0,   0,   0,   0, 128,  63,   0,   0, 112,  65, _
              0, 255, 127,  71,   0,   0, 128,  59,   0,   0, _
            128,  47,  73,  70, 131,   5,  75,   6, 158,  63, _
             77,   6, 158,  63,  80,   6, 158,  63,  30,  55, _
            190, 121, 255, 255, 127, 255, 255, 127, 127,   1, _
              0,   0,   0, 192, 255,   0,   0, 128, 255,   0, _
              0, 128, 127 }

        Console.WriteLine( _
            "This example of the BitConverter.ToSingle( Byte( ), " & _
            "Integer ) " & vbCrLf & "method generates the " & _
            "following output. It converts elements " & vbCrLf & _
            "of a Byte array to Single values." & vbCrLf )

        WriteMultiLineByteArray( byteArray )

        Console.WriteLine( formatter, "index", "array elements", _
            "Single" )
        Console.WriteLine( formatter, "-----", "--------------", _
            "------" )
          
        ' Convert Byte array elements to Single values.
        BAToSingle( byteArray, 0 )
        BAToSingle( byteArray, 2 )
        BAToSingle( byteArray, 6 )
        BAToSingle( byteArray, 10 )
        BAToSingle( byteArray, 14 )
        BAToSingle( byteArray, 18 )
        BAToSingle( byteArray, 22 )
        BAToSingle( byteArray, 26 )
        BAToSingle( byteArray, 30 )
        BAToSingle( byteArray, 34 )
        BAToSingle( byteArray, 38 )
        BAToSingle( byteArray, 42 )
        BAToSingle( byteArray, 45 )
        BAToSingle( byteArray, 49 )
        BAToSingle( byteArray, 51 )
        BAToSingle( byteArray, 55 )
        BAToSingle( byteArray, 59 )
    End Sub 
End Module

' This example of the BitConverter.ToSingle( Byte( ), Integer )
' method generates the following output. It converts elements
' of a Byte array to Single values.
' 
' initial Byte array
' ------------------
' 00-00-00-00-80-3F-00-00-70-41-00-FF-7F-47-00-00-80-3B-00-00-
' 80-2F-49-46-83-05-4B-06-9E-3F-4D-06-9E-3F-50-06-9E-3F-1E-37-
' BE-79-FF-FF-7F-FF-FF-7F-7F-01-00-00-00-C0-FF-00-00-80-FF-00-
' 00-80-7F
' 
' index   array elements            Single
' -----   --------------            ------
'     0      00-00-00-00    0.0000000E+000
'     2      00-00-80-3F    1.0000000E+000
'     6      00-00-70-41    1.5000000E+001
'    10      00-FF-7F-47    6.5535000E+004
'    14      00-00-80-3B    3.9062500E-003
'    18      00-00-80-2F    2.3283064E-010
'    22      49-46-83-05    1.2345000E-035
'    26      4B-06-9E-3F    1.2345671E+000
'    30      4D-06-9E-3F    1.2345673E+000
'    34      50-06-9E-3F    1.2345676E+000
'    38      1E-37-BE-79    1.2345679E+035
'    42      FF-FF-7F-FF   -3.4028235E+038
'    45      FF-FF-7F-7F    3.4028235E+038
'    49      01-00-00-00    1.4012985E-045
'    51      00-00-C0-FF               NaN
'    55      00-00-80-FF         -Infinity
'    59      00-00-80-7F          Infinity

Remarques

La ToSingle méthode convertit les octets d’index startIndex en startIndex + 3 en valeur Single . L’ordre des octets dans le tableau doit refléter l’endianité de l’architecture du système informatique. Pour plus d’informations, consultez la section Notes de BitConverter.

Voir aussi

S’applique à