BitConverter.ToDouble Method

Definition

Overloads

ToDouble(ReadOnlySpan<Byte>)

Converts a read-only byte span into a double-precision floating-point value.

ToDouble(Byte[], Int32)

Returns a double-precision floating point number converted from eight bytes at a specified position in a byte array.

ToDouble(ReadOnlySpan<Byte>)

Source:
BitConverter.cs
Source:
BitConverter.cs
Source:
BitConverter.cs

Converts a read-only byte span into a double-precision floating-point value.

public static double ToDouble (ReadOnlySpan<byte> value);

Parameters

value
ReadOnlySpan<Byte>

A read-only span containing the bytes to convert.

Returns

A double-precision floating-point value that represents the converted bytes.

Exceptions

The length of value is less than the length of a Double value.

Applies to

.NET 9 dan versi lain
Produk Versi
.NET Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Standard 2.1

ToDouble(Byte[], Int32)

Source:
BitConverter.cs
Source:
BitConverter.cs
Source:
BitConverter.cs

Returns a double-precision floating point number converted from eight bytes at a specified position in a byte array.

public static double ToDouble (byte[] value, int startIndex);

Parameters

value
Byte[]

An array of bytes that includes the eight bytes to convert.

startIndex
Int32

The starting position within value.

Returns

A double-precision floating point number formed by eight bytes beginning at startIndex.

Exceptions

startIndex is greater than or equal to the length of value minus 7, and is less than or equal to the length of value minus 1.

value is null.

startIndex is less than zero or greater than the length of value minus 1.

Examples

The following code example converts elements of Byte arrays to Double values with the ToDouble method.

// 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
*/

Remarks

The ToDouble method converts the bytes from index startIndex to startIndex + 7 to a Double value. The order of bytes in the array must reflect the endianness of the computer system's architecture. For more information, see the Remarks section of the BitConverter class topic.

See also

Applies to

.NET 9 dan versi lain
Produk Versi
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1
UWP 10.0