BitConverter.ToInt64 Method

Definition

Overloads

ToInt64(ReadOnlySpan<Byte>)

Converts a read-only byte span into a 64-bit signed integer.

ToInt64(Byte[], Int32)

Returns a 64-bit signed integer converted from eight bytes at a specified position in a byte array.

ToInt64(ReadOnlySpan<Byte>)

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

Converts a read-only byte span into a 64-bit signed integer.

public static long ToInt64 (ReadOnlySpan<byte> value);

Parameters

value
ReadOnlySpan<Byte>

A read-only span containing the bytes to convert.

Returns

A 64-bit signed integer representing the converted bytes.

Exceptions

The length of value is less than 8.

Applies to

.NET 9 和其他版本
产品 版本
.NET Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Standard 2.1

ToInt64(Byte[], Int32)

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

Returns a 64-bit signed integer converted from eight bytes at a specified position in a byte array.

public static long ToInt64 (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 64-bit signed integer 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 Int64 values with the ToInt64 method.

// Example of the BitConverter.ToInt64 method.
using System;

class BytesToInt64Demo
{
    const string formatter = "{0,5}{1,27}{2,24}";

    // Convert eight byte array elements to a long and display it.
    public static void BAToInt64( byte[ ] bytes, int index )
    {
        long value = BitConverter.ToInt64( 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,  54, 101, 196, 255, 255, 255, 255,   0,   0,
              0,   0,   0,   0,   0,   0, 128,   0, 202, 154,
             59,   0,   0,   0,   0,   1,   0,   0,   0,   0,
            255, 255, 255, 255,   1,   0,   0, 255, 255, 255,
            255, 255, 255, 255, 127,  86,  85,  85,  85,  85,
             85, 255, 255, 170, 170, 170, 170, 170, 170,   0,
              0, 100, 167, 179, 182, 224,  13,   0,   0, 156,
             88,  76,  73,  31, 242 };

        Console.WriteLine(
            "This example of the BitConverter.ToInt64( byte[ ], " +
            "int ) \nmethod generates the following output. It " +
            "converts elements \nof a byte array to long values.\r\n" );

        WriteMultiLineByteArray( byteArray );

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

        // Convert byte array elements to long values.
        BAToInt64( byteArray, 8 );
        BAToInt64( byteArray, 5 );
        BAToInt64( byteArray, 34 );
        BAToInt64( byteArray, 17 );
        BAToInt64( byteArray, 0 );
        BAToInt64( byteArray, 21 );
        BAToInt64( byteArray, 26 );
        BAToInt64( byteArray, 53 );
        BAToInt64( byteArray, 45 );
        BAToInt64( byteArray, 59 );
        BAToInt64( byteArray, 67 );
        BAToInt64( byteArray, 37 );
        BAToInt64( byteArray, 9 );
    }
}

/*
This example of the BitConverter.ToInt64( byte[ ], int )
method generates the following output. It converts elements
of a byte array to long values.

initial byte array
------------------
00-36-65-C4-FF-FF-FF-FF-00-00-00-00-00-00-00-00-80-00-CA-9A-
3B-00-00-00-00-01-00-00-00-00-FF-FF-FF-FF-01-00-00-FF-FF-FF-
FF-FF-FF-FF-7F-56-55-55-55-55-55-FF-FF-AA-AA-AA-AA-AA-AA-00-
00-64-A7-B3-B6-E0-0D-00-00-9C-58-4C-49-1F-F2

index             array elements                    long
-----             --------------                    ----
    8    00-00-00-00-00-00-00-00                       0
    5    FF-FF-FF-00-00-00-00-00                16777215
   34    01-00-00-FF-FF-FF-FF-FF               -16777215
   17    00-CA-9A-3B-00-00-00-00              1000000000
    0    00-36-65-C4-FF-FF-FF-FF             -1000000000
   21    00-00-00-00-01-00-00-00              4294967296
   26    00-00-00-00-FF-FF-FF-FF             -4294967296
   53    AA-AA-AA-AA-AA-AA-00-00         187649984473770
   45    56-55-55-55-55-55-FF-FF        -187649984473770
   59    00-00-64-A7-B3-B6-E0-0D     1000000000000000000
   67    00-00-9C-58-4C-49-1F-F2    -1000000000000000000
   37    FF-FF-FF-FF-FF-FF-FF-7F     9223372036854775807
    9    00-00-00-00-00-00-00-80    -9223372036854775808
*/

Remarks

The ToInt64 method converts the bytes from index startIndex to startIndex + 7 to a Int64 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 和其他版本
产品 版本
.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