BitConverter.ToDouble Metodo
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Overload
| ToDouble(ReadOnlySpan<Byte>) |
Converte un intervallo di byte di sola lettura in un valore a virgola mobile e precisione doppia. |
| ToDouble(Byte[], Int32) |
Restituisce un numero in virgola mobile e precisione doppia convertito da otto byte nella posizione specificata in una matrice di byte. |
ToDouble(ReadOnlySpan<Byte>)
Converte un intervallo di byte di sola lettura in un valore a virgola mobile e precisione doppia.
public:
static double ToDouble(ReadOnlySpan<System::Byte> value);public static double ToDouble (ReadOnlySpan<byte> value);static member ToDouble : ReadOnlySpan<byte> -> doublePublic Shared Function ToDouble (value As ReadOnlySpan(Of Byte)) As DoubleParametri
- value
- ReadOnlySpan<Byte>
Intervallo di sola lettura contenente i byte da convertire.
Restituisce
Valore a virgola mobile e precisione doppia che rappresenta i byte convertiti.
Eccezioni
La lunghezza di value è minore della lunghezza di un valore Double.
Si applica a
ToDouble(Byte[], Int32)
Restituisce un numero in virgola mobile e precisione doppia convertito da otto byte nella posizione specificata in una matrice di byte.
public:
static double ToDouble(cli::array <System::Byte> ^ value, int startIndex);public static double ToDouble (byte[] value, int startIndex);static member ToDouble : byte[] * int -> doublePublic Shared Function ToDouble (value As Byte(), startIndex As Integer) As DoubleParametri
- value
- Byte[]
Matrice di byte che include gli otto byte da convertire.
- startIndex
- Int32
Posizione iniziale all'interno di value.
Restituisce
Numero a virgola mobile a precisione doppia formato da otto byte a partire da startIndex.
Eccezioni
startIndex è maggiore o uguale alla lunghezza di value meno 7 e minore o uguale alla lunghezza di value meno 1.
value è null.
startIndexè minore di zero o maggiore della lunghezza di value meno 1.
Esempio
Nell'esempio di codice seguente vengono convertiti elementi di Byte matrici in Double valori con il ToDouble metodo .
// Example of the BitConverter::ToDouble method.
using namespace System;
// Convert eight byte array elements to a double and display it.
void BAToDouble( array<unsigned char>^bytes, int index )
{
double value = BitConverter::ToDouble( bytes, index );
Console::WriteLine( "{0,5}{1,27}{2,27:E16}", index, BitConverter::ToString( bytes, index, 8 ), 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 = {0,0,0,0,0,0,0,0,240,63,0,0,0,0,0,224,111,64,0,0,224,255,255,255,239,65,0,0,0,0,0,0,112,63,0,0,0,0,0,0,240,61,223,136,30,28,254,116,170,1,250,89,140,66,202,192,243,63,251,89,140,66,202,192,243,63,252,89,140,66,202,192,243,63,82,211,187,188,232,126,61,126,255,255,255,255,255,255,239,255,255,255,255,255,255,239,127,1,0,0,0,0,0,0,0,248,255,0,0,0,0,0,0,240,255,0,0,0,0,0,0,240,127};
Console::WriteLine( "This example of the BitConverter::ToDouble( unsigned "
"char[ ], int ) \nmethod generates the following output. It "
"converts elements of a \nbyte array to double values.\n" );
WriteMultiLineByteArray( byteArray );
Console::WriteLine( "{0,5}{1,27}{2,27:E16}", "index", "array elements", "double" );
Console::WriteLine( "{0,5}{1,27}{2,27:E16}", "-----", "--------------", "------" );
// Convert byte array elements to double values.
BAToDouble( byteArray, 0 );
BAToDouble( byteArray, 2 );
BAToDouble( byteArray, 10 );
BAToDouble( byteArray, 18 );
BAToDouble( byteArray, 26 );
BAToDouble( byteArray, 34 );
BAToDouble( byteArray, 42 );
BAToDouble( byteArray, 50 );
BAToDouble( byteArray, 58 );
BAToDouble( byteArray, 66 );
BAToDouble( byteArray, 74 );
BAToDouble( byteArray, 82 );
BAToDouble( byteArray, 89 );
BAToDouble( byteArray, 97 );
BAToDouble( byteArray, 99 );
BAToDouble( byteArray, 107 );
BAToDouble( byteArray, 115 );
}
/*
This example of the BitConverter.ToDouble( byte( ), int )
method generates the following output. It converts elements
of a byte array to double values.
initial byte array
------------------
00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
E0-FF-FF-FF-EF-41-00-00-00-00-00-00-70-3F-00-00-00-00-00-00-
F0-3D-DF-88-1E-1C-FE-74-AA-01-FA-59-8C-42-CA-C0-F3-3F-FB-59-
8C-42-CA-C0-F3-3F-FC-59-8C-42-CA-C0-F3-3F-52-D3-BB-BC-E8-7E-
3D-7E-FF-FF-FF-FF-FF-FF-EF-FF-FF-FF-FF-FF-FF-EF-7F-01-00-00-
00-00-00-00-00-F8-FF-00-00-00-00-00-00-F0-FF-00-00-00-00-00-
00-F0-7F
index array elements double
----- -------------- ------
0 00-00-00-00-00-00-00-00 0.0000000000000000E+000
2 00-00-00-00-00-00-F0-3F 1.0000000000000000E+000
10 00-00-00-00-00-E0-6F-40 2.5500000000000000E+002
18 00-00-E0-FF-FF-FF-EF-41 4.2949672950000000E+009
26 00-00-00-00-00-00-70-3F 3.9062500000000000E-003
34 00-00-00-00-00-00-F0-3D 2.3283064365386963E-010
42 DF-88-1E-1C-FE-74-AA-01 1.2345678901234500E-300
50 FA-59-8C-42-CA-C0-F3-3F 1.2345678901234565E+000
58 FB-59-8C-42-CA-C0-F3-3F 1.2345678901234567E+000
66 FC-59-8C-42-CA-C0-F3-3F 1.2345678901234569E+000
74 52-D3-BB-BC-E8-7E-3D-7E 1.2345678901234569E+300
82 FF-FF-FF-FF-FF-FF-EF-FF -1.7976931348623157E+308
89 FF-FF-FF-FF-FF-FF-EF-7F 1.7976931348623157E+308
97 01-00-00-00-00-00-00-00 4.9406564584124654E-324
99 00-00-00-00-00-00-F8-FF NaN
107 00-00-00-00-00-00-F0-FF -Infinity
115 00-00-00-00-00-00-F0-7F Infinity
*/
// Example of the BitConverter.ToDouble method.
using System;
class BytesToDoubleDemo
{
const string formatter = "{0,5}{1,27}{2,27:E16}";
// Convert eight byte array elements to a double and display it.
public static void BAToDouble( byte[ ] bytes, int index )
{
double value = BitConverter.ToDouble( bytes, index );
Console.WriteLine( formatter, index,
BitConverter.ToString( bytes, index, 8 ), 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, 0, 0, 0, 0, 240, 63,
0, 0, 0, 0, 0, 224, 111, 64, 0, 0,
224, 255, 255, 255, 239, 65, 0, 0, 0, 0,
0, 0, 112, 63, 0, 0, 0, 0, 0, 0,
240, 61, 223, 136, 30, 28, 254, 116, 170, 1,
250, 89, 140, 66, 202, 192, 243, 63, 251, 89,
140, 66, 202, 192, 243, 63, 252, 89, 140, 66,
202, 192, 243, 63, 82, 211, 187, 188, 232, 126,
61, 126, 255, 255, 255, 255, 255, 255, 239, 255,
255, 255, 255, 255, 255, 239, 127, 1, 0, 0,
0, 0, 0, 0, 0, 248, 255, 0, 0, 0,
0, 0, 0, 240, 255, 0, 0, 0, 0, 0,
0, 240, 127 };
Console.WriteLine(
"This example of the BitConverter.ToDouble( byte[ ], " +
"int ) \nmethod generates the following output. It " +
"converts elements \nof a byte array to double values.\n" );
WriteMultiLineByteArray( byteArray );
Console.WriteLine( formatter, "index", "array elements",
"double" );
Console.WriteLine( formatter, "-----", "--------------",
"------" );
// Convert byte array elements to double values.
BAToDouble( byteArray, 0 );
BAToDouble( byteArray, 2 );
BAToDouble( byteArray, 10 );
BAToDouble( byteArray, 18 );
BAToDouble( byteArray, 26 );
BAToDouble( byteArray, 34 );
BAToDouble( byteArray, 42 );
BAToDouble( byteArray, 50 );
BAToDouble( byteArray, 58 );
BAToDouble( byteArray, 66 );
BAToDouble( byteArray, 74 );
BAToDouble( byteArray, 82 );
BAToDouble( byteArray, 89 );
BAToDouble( byteArray, 97 );
BAToDouble( byteArray, 99 );
BAToDouble( byteArray, 107 );
BAToDouble( byteArray, 115 );
}
}
/*
This example of the BitConverter.ToDouble( byte[ ], int )
method generates the following output. It converts elements
of a byte array to double values.
initial byte array
------------------
00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
E0-FF-FF-FF-EF-41-00-00-00-00-00-00-70-3F-00-00-00-00-00-00-
F0-3D-DF-88-1E-1C-FE-74-AA-01-FA-59-8C-42-CA-C0-F3-3F-FB-59-
8C-42-CA-C0-F3-3F-FC-59-8C-42-CA-C0-F3-3F-52-D3-BB-BC-E8-7E-
3D-7E-FF-FF-FF-FF-FF-FF-EF-FF-FF-FF-FF-FF-FF-EF-7F-01-00-00-
00-00-00-00-00-F8-FF-00-00-00-00-00-00-F0-FF-00-00-00-00-00-
00-F0-7F
index array elements double
----- -------------- ------
0 00-00-00-00-00-00-00-00 0.0000000000000000E+000
2 00-00-00-00-00-00-F0-3F 1.0000000000000000E+000
10 00-00-00-00-00-E0-6F-40 2.5500000000000000E+002
18 00-00-E0-FF-FF-FF-EF-41 4.2949672950000000E+009
26 00-00-00-00-00-00-70-3F 3.9062500000000000E-003
34 00-00-00-00-00-00-F0-3D 2.3283064365386963E-010
42 DF-88-1E-1C-FE-74-AA-01 1.2345678901234500E-300
50 FA-59-8C-42-CA-C0-F3-3F 1.2345678901234565E+000
58 FB-59-8C-42-CA-C0-F3-3F 1.2345678901234567E+000
66 FC-59-8C-42-CA-C0-F3-3F 1.2345678901234569E+000
74 52-D3-BB-BC-E8-7E-3D-7E 1.2345678901234569E+300
82 FF-FF-FF-FF-FF-FF-EF-FF -1.7976931348623157E+308
89 FF-FF-FF-FF-FF-FF-EF-7F 1.7976931348623157E+308
97 01-00-00-00-00-00-00-00 4.9406564584124654E-324
99 00-00-00-00-00-00-F8-FF NaN
107 00-00-00-00-00-00-F0-FF -Infinity
115 00-00-00-00-00-00-F0-7F Infinity
*/
open System
let print obj1 obj2 obj3 = printfn $"{obj1,5}{obj2,27}{obj3,27:E16}"
// Convert eight byte array elements to a double and display it.
let BAToDouble bytes index =
let value = BitConverter.ToDouble(bytes, index)
print index (BitConverter.ToString(bytes, index, 8)) 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; 0uy; 0uy; 0uy; 0uy; 240uy; 63uy
0uy; 0uy; 0uy; 0uy; 0uy; 224uy; 111uy; 64uy; 0uy; 0uy;
224uy; 255uy; 255uy; 255uy; 239uy; 65uy; 0uy; 0uy; 0uy; 0uy
0uy; 0uy; 112uy; 63uy; 0uy; 0uy; 0uy; 0uy; 0uy; 0uy
240uy; 61uy; 223uy; 136uy; 30uy; 28uy; 254uy; 116uy; 170uy; 1uy
250uy; 89uy; 140uy; 66uy; 202uy; 192uy; 243uy; 63uy; 251uy; 89uy
140uy; 66uy; 202uy; 192uy; 243uy; 63uy; 252uy; 89uy; 140uy; 66uy
202uy; 192uy; 243uy; 63uy; 82uy; 211uy; 187uy; 188uy; 232uy; 126uy
61uy; 126uy; 255uy; 255uy; 255uy; 255uy; 255uy; 255uy; 239uy; 255uy
255uy; 255uy; 255uy; 255uy; 255uy; 239uy; 127uy; 1uy; 0uy; 0uy
0uy; 0uy; 0uy; 0uy; 0uy; 248uy; 255uy; 0uy; 0uy; 0uy
0uy; 0uy; 0uy; 240uy; 255uy; 0uy; 0uy; 0uy; 0uy; 0uy
0uy; 240uy; 127uy |]
printfn "This example of the BitConverter.ToDouble(byte [], int) \nmethod generates the following output. It converts elements \nof a byte array to double values.\n"
writeMultiLineByteArray byteArray
print "index" "array elements" "double"
print "-----" "--------------" "------"
// Convert byte array elements to double values.
BAToDouble byteArray 0
BAToDouble byteArray 2
BAToDouble byteArray 10
BAToDouble byteArray 18
BAToDouble byteArray 26
BAToDouble byteArray 34
BAToDouble byteArray 42
BAToDouble byteArray 50
BAToDouble byteArray 58
BAToDouble byteArray 66
BAToDouble byteArray 74
BAToDouble byteArray 82
BAToDouble byteArray 89
BAToDouble byteArray 97
BAToDouble byteArray 99
BAToDouble byteArray 107
BAToDouble byteArray 115
// This example of the BitConverter.ToDouble(byte [], int )
// method generates the following output. It converts elements
// of a byte array to double values.
// initial byte array
// ------------------
// 00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
// 00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
// E0-FF-FF-FF-EF-41-00-00-00-00-00-00-70-3F-00-00-00-00-00-00-
// F0-3D-DF-88-1E-1C-FE-74-AA-01-FA-59-8C-42-CA-C0-F3-3F-FB-59-
// 8C-42-CA-C0-F3-3F-FC-59-8C-42-CA-C0-F3-3F-52-D3-BB-BC-E8-7E-
// 3D-7E-FF-FF-FF-FF-FF-FF-EF-FF-FF-FF-FF-FF-FF-EF-7F-01-00-00-
// 00-F0-7F
//
// index array elements double
// ----- -------------- ------
// 0 00-00-00-00-00-00-00-00 0.0000000000000000E+000
// 2 00-00-00-00-00-00-F0-3F 1.0000000000000000E+000
// 10 00-00-00-00-00-E0-6F-40 2.5500000000000000E+002
// 18 00-00-E0-FF-FF-FF-EF-41 4.2949672950000000E+009
// 26 00-00-00-00-00-00-70-3F 3.9062500000000000E-003
// 34 00-00-00-00-00-00-F0-3D 2.3283064365386963E-010
// 42 DF-88-1E-1C-FE-74-AA-01 1.2345678901234500E-300
// 50 FA-59-8C-42-CA-C0-F3-3F 1.2345678901234565E+000
// 58 FB-59-8C-42-CA-C0-F3-3F 1.2345678901234567E+000
// 66 FC-59-8C-42-CA-C0-F3-3F 1.2345678901234569E+000
// 74 52-D3-BB-BC-E8-7E-3D-7E 1.2345678901234569E+300
// 82 FF-FF-FF-FF-FF-FF-EF-FF -1.7976931348623157E+308
// 89 FF-FF-FF-FF-FF-FF-EF-7F 1.7976931348623157E+308
// 97 01-00-00-00-00-00-00-00 4.9406564584124654E-324
// 99 00-00-00-00-00-00-F8-FF NaN
// 107 00-00-00-00-00-00-F0-FF -∞
// 115 00-00-00-00-00-00-F0-7F ∞
' Example of the BitConverter.ToDouble method.
Module BytesToDoubleDemo
Const formatter As String = "{0,5}{1,27}{2,27:E16}"
' Convert eight Byte array elements to a Double and display it.
Sub BAToDouble( bytes( ) As Byte, index As Integer )
Dim value As Double = BitConverter.ToDouble( bytes, index )
Console.WriteLine( formatter, index, _
BitConverter.ToString( bytes, index, 8 ), 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, 0, 0, 0, 0, 240, 63, _
0, 0, 0, 0, 0, 224, 111, 64, 0, 0, _
224, 255, 255, 255, 239, 65, 0, 0, 0, 0, _
0, 0, 112, 63, 0, 0, 0, 0, 0, 0, _
240, 61, 223, 136, 30, 28, 254, 116, 170, 1, _
250, 89, 140, 66, 202, 192, 243, 63, 251, 89, _
140, 66, 202, 192, 243, 63, 252, 89, 140, 66, _
202, 192, 243, 63, 82, 211, 187, 188, 232, 126, _
61, 126, 255, 255, 255, 255, 255, 255, 239, 255, _
255, 255, 255, 255, 255, 239, 127, 1, 0, 0, _
0, 0, 0, 0, 0, 248, 255, 0, 0, 0, _
0, 0, 0, 240, 255, 0, 0, 0, 0, 0, _
0, 240, 127 }
Console.WriteLine( _
"This example of the BitConverter.ToDouble( Byte( ), " & _
"Integer ) " & vbCrLf & "method generates the " & _
"following output. It converts elements " & vbCrLf & _
"of a Byte array to Double values." & vbCrLf )
WriteMultiLineByteArray( byteArray )
Console.WriteLine( formatter, "index", "array elements", _
"Double" )
Console.WriteLine( formatter, "-----", "--------------", _
"------" )
' Convert Byte array elements to Double values.
BAToDouble( byteArray, 0 )
BAToDouble( byteArray, 2 )
BAToDouble( byteArray, 10 )
BAToDouble( byteArray, 18 )
BAToDouble( byteArray, 26 )
BAToDouble( byteArray, 34 )
BAToDouble( byteArray, 42 )
BAToDouble( byteArray, 50 )
BAToDouble( byteArray, 58 )
BAToDouble( byteArray, 66 )
BAToDouble( byteArray, 74 )
BAToDouble( byteArray, 82 )
BAToDouble( byteArray, 89 )
BAToDouble( byteArray, 97 )
BAToDouble( byteArray, 99 )
BAToDouble( byteArray, 107 )
BAToDouble( byteArray, 115 )
End Sub
End Module
' This example of the BitConverter.ToDouble( Byte( ), Integer )
' method generates the following output. It converts elements
' of a Byte array to Double values.
'
' initial Byte array
' ------------------
' 00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
' E0-FF-FF-FF-EF-41-00-00-00-00-00-00-70-3F-00-00-00-00-00-00-
' F0-3D-DF-88-1E-1C-FE-74-AA-01-FA-59-8C-42-CA-C0-F3-3F-FB-59-
' 8C-42-CA-C0-F3-3F-FC-59-8C-42-CA-C0-F3-3F-52-D3-BB-BC-E8-7E-
' 3D-7E-FF-FF-FF-FF-FF-FF-EF-FF-FF-FF-FF-FF-FF-EF-7F-01-00-00-
' 00-00-00-00-00-F8-FF-00-00-00-00-00-00-F0-FF-00-00-00-00-00-
' 00-F0-7F
'
' index array elements Double
' ----- -------------- ------
' 0 00-00-00-00-00-00-00-00 0.0000000000000000E+000
' 2 00-00-00-00-00-00-F0-3F 1.0000000000000000E+000
' 10 00-00-00-00-00-E0-6F-40 2.5500000000000000E+002
' 18 00-00-E0-FF-FF-FF-EF-41 4.2949672950000000E+009
' 26 00-00-00-00-00-00-70-3F 3.9062500000000000E-003
' 34 00-00-00-00-00-00-F0-3D 2.3283064365386963E-010
' 42 DF-88-1E-1C-FE-74-AA-01 1.2345678901234500E-300
' 50 FA-59-8C-42-CA-C0-F3-3F 1.2345678901234565E+000
' 58 FB-59-8C-42-CA-C0-F3-3F 1.2345678901234567E+000
' 66 FC-59-8C-42-CA-C0-F3-3F 1.2345678901234569E+000
' 74 52-D3-BB-BC-E8-7E-3D-7E 1.2345678901234569E+300
' 82 FF-FF-FF-FF-FF-FF-EF-FF -1.7976931348623157E+308
' 89 FF-FF-FF-FF-FF-FF-EF-7F 1.7976931348623157E+308
' 97 01-00-00-00-00-00-00-00 4.9406564584124654E-324
' 99 00-00-00-00-00-00-F8-FF NaN
' 107 00-00-00-00-00-00-F0-FF -Infinity
' 115 00-00-00-00-00-00-F0-7F Infinity
Commenti
Il ToDouble metodo converte i byte dall'indice startIndex a startIndex + 7 in un Double valore. L'ordine dei byte nella matrice deve riflettere l'endianità dell'architettura del sistema computer. Per altre informazioni, vedere la sezione Osservazioni dell'argomento BitConverter della classe.