BitConverter.ToUInt64 Method
Returns a 64-bit unsigned integer converted from eight bytes at a specified position in a byte array.
Assembly: mscorlib (in mscorlib.dll)
[CLSCompliantAttribute(false)] public static ulong ToUInt64( byte[] value, int startIndex )
Parameters
- value
- Type: System.Byte[]
An array of bytes.
- startIndex
- Type: System.Int32
The starting position within value.
Return Value
Type: System.UInt64A 64-bit unsigned integer formed by the eight bytes beginning at startIndex.
| Exception | Condition |
|---|---|
| ArgumentException | 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. |
| ArgumentNullException | value is null. |
| ArgumentOutOfRangeException | startIndex is less than zero or greater than the length of value minus 1. |
The ToUInt64 method converts the bytes from index startIndex to startIndex + 7 to a UInt64 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.
The following code example converts elements of Byte arrays to UInt64 values with the ToUInt64 method.
// Example of the BitConverter.ToUInt64 method. using System; class BytesToUInt64Demo { const string formatter = "{0,5}{1,27}{2,24}"; // Convert eight byte array elements to a ulong and display it. public static void BAToUInt64( byte[ ] bytes, int index ) { ulong value = BitConverter.ToUInt64( 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 = { 255, 255, 255, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 100, 167, 179, 182, 224, 13, 0, 202, 154, 59, 0, 0, 0, 0, 170, 170, 170, 170, 170, 170, 0, 0, 232, 137, 4, 35, 199, 138, 255, 255, 255, 255, 255, 255, 255, 255, 127 }; Console.WriteLine( "This example of the BitConverter.ToUInt64( byte[ ], " + "int ) \nmethod generates the following output. It " + "converts elements \nof a byte array to ulong values.\n" ); WriteMultiLineByteArray( byteArray ); Console.WriteLine( formatter, "index", "array elements", "ulong" ); Console.WriteLine( formatter, "-----", "--------------", "------" ); // Convert byte array elements to ulong values. BAToUInt64( byteArray, 3 ); BAToUInt64( byteArray, 0 ); BAToUInt64( byteArray, 21 ); BAToUInt64( byteArray, 7 ); BAToUInt64( byteArray, 29 ); BAToUInt64( byteArray, 13 ); BAToUInt64( byteArray, 35 ); BAToUInt64( byteArray, 44 ); BAToUInt64( byteArray, 43 ); } } /* This example of the BitConverter.ToUInt64( byte[ ], int ) method generates the following output. It converts elements of a byte array to ulong values. initial byte array ------------------ FF-FF-FF-00-00-00-00-00-00-00-00-01-00-00-00-64-A7-B3-B6-E0- 0D-00-CA-9A-3B-00-00-00-00-AA-AA-AA-AA-AA-AA-00-00-E8-89-04- 23-C7-8A-FF-FF-FF-FF-FF-FF-FF-FF-7F index array elements ulong ----- -------------- ------ 3 00-00-00-00-00-00-00-00 0 0 FF-FF-FF-00-00-00-00-00 16777215 21 00-CA-9A-3B-00-00-00-00 1000000000 7 00-00-00-00-01-00-00-00 4294967296 29 AA-AA-AA-AA-AA-AA-00-00 187649984473770 13 00-00-64-A7-B3-B6-E0-0D 1000000000000000000 35 00-00-E8-89-04-23-C7-8A 10000000000000000000 44 FF-FF-FF-FF-FF-FF-FF-7F 9223372036854775807 43 FF-FF-FF-FF-FF-FF-FF-FF 18446744073709551615 */
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
