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BitConverter.ToSingle Metoda

Definice

Přetížení

ToSingle(ReadOnlySpan<Byte>)

Převede bajt jen pro čtení na hodnotu s plovoucí desetinou čárkou.

ToSingle(Byte[], Int32)

Vrátí jednoúčelové číslo s plovoucí desetinou čárkou převedené ze čtyř bajtů na zadané pozici v bajtovém poli.

ToSingle(ReadOnlySpan<Byte>)

Převede bajt jen pro čtení na hodnotu s plovoucí desetinou čárkou.

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

Parametry

value
ReadOnlySpan<Byte>

Rozsah jen pro čtení obsahující bajty, které se mají převést.

Návraty

Single

Hodnota s plovoucí desetinabídkou s jednou přesností představující převedené bajty.

Výjimky

Délka value je menší než délka Single hodnoty.

Platí pro

ToSingle(Byte[], Int32)

Vrátí jednoúčelové číslo s plovoucí desetinou čárkou převedené ze čtyř bajtů na zadané pozici v bajtovém poli.

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

Parametry

value
Byte[]

Pole bajtů.

startIndex
Int32

Počáteční pozice uvnitř value.

Návraty

Single

Jednoúčelové číslo s plovoucí desetinou čárkou tvořené čtyřmi bajty počínaje startIndex.

Výjimky

startIndex je větší než nebo rovno délce value minus 3 a je menší nebo rovno délce value minus 1.

value je null.

startIndex je menší než nula nebo větší než délka value minus 1.

Příklady

Následující příklad kódu převede prvky Byte polí na Single hodnoty pomocí ToSingle metody.

// 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

Poznámky

Metoda ToSingle převede bajty z indexu startIndex na startIndex + 3 na Single hodnotu. Pořadí bajtů v poli musí odrážet endianitu architektury počítačového systému. Další informace naleznete v části Poznámky v části BitConverter.

Viz také

Platí pro