BitConverter.ToSingle 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
多載
| ToSingle(ReadOnlySpan<Byte>) |
將唯讀位元組範圍轉換成單精確度浮點值。 |
| ToSingle(Byte[], Int32) |
傳回從位元組陣列中指定位置的四個位元組所轉換的單精確度浮點數。 |
ToSingle(ReadOnlySpan<Byte>)
將唯讀位元組範圍轉換成單精確度浮點值。
public:
static float ToSingle(ReadOnlySpan<System::Byte> value);public static float ToSingle (ReadOnlySpan<byte> value);static member ToSingle : ReadOnlySpan<byte> -> singlePublic Shared Function ToSingle (value As ReadOnlySpan(Of Byte)) As Single參數
- value
- ReadOnlySpan<Byte>
包含要轉換之位元組的唯讀範圍。
傳回
單精確度浮點值，表示已轉換的位元組。
例外狀況
value 的長度小於 Single 值的長度。
適用於
ToSingle(Byte[], Int32)
傳回從位元組陣列中指定位置的四個位元組所轉換的單精確度浮點數。
public:
static float ToSingle(cli::array <System::Byte> ^ value, int startIndex);public static float ToSingle (byte[] value, int startIndex);static member ToSingle : byte[] * int -> singlePublic Shared Function ToSingle (value As Byte(), startIndex As Integer) As Single參數
- value
- Byte[]
位元組陣列。
- startIndex
- Int32
開始位置在 value 內。
傳回
由四個位元組所形成的單精確度浮點數開始於 startIndex。
例外狀況
startIndex 大於或等於 value 的長度減去 3，而且小於或等於 value 的長度減去 1。
value 為 null。
startIndex 小於零或大於 value 的長度減去 1。
範例
下列程式碼範例會使用 ToSingle 方法，將陣列的專案 Byte 轉換為 Single 值。
// 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
備註
方法 ToSingle 會將位元組從索引 startIndex 轉換成 startIndex + 3 轉換為 Single 值。 陣列中的位元組順序必須反映電腦系統架構的結束度。 如需詳細資訊，請參閱 的 BitConverter 一節。
