ToUInt64 Method

BitConverter.ToUInt64 Method

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

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

This API is not CLS-compliant. 

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
<CLSCompliantAttribute(False)> _
Public Shared Function ToUInt64 ( _
	value As Byte(), _
	startIndex As Integer _
) As ULong

Parameters

value
Type: System.Byte ()
An array of bytes.
startIndex
Type: System.Int32
The starting position within value.

Return Value

Type: System.UInt64
A 64-bit unsigned integer formed by the eight bytes beginning at startIndex.

ExceptionCondition
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 Nothing.

ArgumentOutOfRangeException

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

The following code example converts elements of Byte arrays to UInt64 values with the ToUInt64 method.


' Example of the BitConverter.ToUInt64 method.

Module Example

   Const formatter As String = "{0,5}{1,27}{2,24}"

   ' Convert eight Byte array elements to a UInt64 and display it.
   Sub BAToUInt64(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal bytes() As Byte, ByVal index As Integer)

      Dim value As UInt64 = BitConverter.ToUInt64(bytes, index)

      outputBlock.Text &= String.Format(formatter, index, _
          BitConverter.ToString(bytes, index, 8), value) & vbCrLf
   End Sub

   ' Display a Byte array, using multiple lines if necessary.
   Sub WriteMultiLineByteArray(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal bytes() As Byte)

      Const rowSize As Integer = 20
      Dim iter As Integer

      outputBlock.Text &= "initial Byte array" & vbCrLf
      outputBlock.Text &= "------------------" & vbCrLf

      For iter = 0 To bytes.Length - rowSize - 1 Step rowSize
         outputBlock.Text &= String.Format( _
             BitConverter.ToString(bytes, iter, rowSize))
         outputBlock.Text &= "-" & vbCrLf
      Next iter

      outputBlock.Text &= String.Format(BitConverter.ToString(bytes, iter)) & vbCrLf
      outputBlock.Text &= vbCrLf
   End Sub

   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim byteArray As Byte() = { _
          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}

      outputBlock.Text &= String.Format( _
          "This example of the BitConverter.ToUInt64( Byte( ), " & _
          "Integer ) " & vbCrLf & "method generates the " & _
          "following output. It converts elements " & vbCrLf & _
          "of a Byte array to UInt64 values." & vbCrLf) & vbCrLf

      WriteMultiLineByteArray(outputBlock, byteArray)

      outputBlock.Text &= String.Format(formatter, "index", "array elements", _
          "UInt64") & vbCrLf
      outputBlock.Text &= String.Format(formatter, "-----", "--------------", _
          "------") & vbCrLf

      ' Convert Byte array elements to UInt64 values.
      BAToUInt64(outputBlock, byteArray, 3)
      BAToUInt64(outputBlock, byteArray, 0)
      BAToUInt64(outputBlock, byteArray, 21)
      BAToUInt64(outputBlock, byteArray, 7)
      BAToUInt64(outputBlock, byteArray, 29)
      BAToUInt64(outputBlock, byteArray, 13)
      BAToUInt64(outputBlock, byteArray, 35)
      BAToUInt64(outputBlock, byteArray, 44)
      BAToUInt64(outputBlock, byteArray, 43)
   End Sub
End Module

' This example of the BitConverter.ToUInt64( Byte( ), Integer )
' method generates the following output. It converts elements
' of a Byte array to UInt64 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                  UInt64
' -----             --------------                  ------
'     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 Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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