BitArray Class

BitArray Class

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

Manages a compact array of bit values, which are represented as Booleans, where true indicates that the bit is on (1) and false indicates the bit is off (0).

System.Object
  System.Collections.BitArray

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

'Declaration
Public NotInheritable Class BitArray _
	Implements ICollection, IEnumerable

The BitArray type exposes the following members.

  NameDescription
Public methodBitArray(BitArray)Initializes a new instance of the BitArray class that contains bit values copied from the specified BitArray.
Public methodBitArray(Boolean())Initializes a new instance of the BitArray class that contains bit values copied from the specified array of Booleans.
Public methodBitArray(Byte())Initializes a new instance of the BitArray class that contains bit values copied from the specified array of bytes.
Public methodBitArray(Int32)Initializes a new instance of the BitArray class that can hold the specified number of bit values, which are initially set to false.
Public methodBitArray(Int32())Initializes a new instance of the BitArray class that contains bit values copied from the specified array of 32-bit integers.
Public methodBitArray(Int32, Boolean)Initializes a new instance of the BitArray class that can hold the specified number of bit values, which are initially set to the specified value.
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  NameDescription
Public propertyCountGets the number of elements contained in the BitArray.
Public propertyIsReadOnlyGets a value indicating whether the BitArray is read-only.
Public propertyIsSynchronizedGets a value indicating whether access to the BitArray is synchronized (thread safe).
Public propertyItemGets or sets the value of the bit at a specific position in the BitArray.
Public propertyLengthGets or sets the number of elements in the BitArray.
Public propertySyncRootGets an object that can be used to synchronize access to the BitArray.
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  NameDescription
Public methodAndPerforms the bitwise AND operation on the elements in the current BitArray against the corresponding elements in the specified BitArray.
Public methodCloneCreates a shallow copy of the BitArray.
Public methodCopyToCopies the entire BitArray to a compatible one-dimensional Array, starting at the specified index of the target array.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetGets the value of the bit at a specific position in the BitArray.
Public methodGetEnumeratorReturns an enumerator that iterates through the BitArray.
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodNotInverts all the bit values in the current BitArray, so that elements set to true are changed to false, and elements set to false are changed to true.
Public methodOrPerforms the bitwise OR operation on the elements in the current BitArray against the corresponding elements in the specified BitArray.
Public methodSetSets the bit at a specific position in the BitArray to the specified value.
Public methodSetAllSets all bits in the BitArray to the specified value.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodXorPerforms the bitwise exclusive OR operation on the elements in the current BitArray against the corresponding elements in the specified BitArray.
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  NameDescription
Public Extension MethodAsQueryableConverts an IEnumerable to an IQueryable. (Defined by Queryable.)
Public Extension MethodCast(Of TResult)Converts the elements of an IEnumerable to the specified type. (Defined by Enumerable.)
Public Extension MethodOfType(Of TResult)Filters the elements of an IEnumerable based on a specified type. (Defined by Enumerable.)
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The size of a BitArray is controlled by the client; indexing past the end of the BitArray throws an ArgumentException.

Elements in this collection can be accessed using an integer index. Indexes in this collection are zero-based.

The following code example shows how to create and initialize a BitArray and how to print out its values.


Imports System.Collections

Public Class Example

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      ' Creates and initializes several BitArrays.
      Dim myBA1 As New BitArray(5)

      Dim myBA2 As New BitArray(5, False)

      Dim myBytes() As Byte = {1, 2, 3, 4, 5}
      Dim myBA3 As New BitArray(myBytes)

      Dim myBools() As Boolean = {True, False, True, True, False}
      Dim myBA4 As New BitArray(myBools)

      Dim myInts() As Integer = {6, 7, 8, 9, 10}
      Dim myBA5 As New BitArray(myInts)

      ' Displays the properties and values of the BitArrays.
      outputBlock.Text &= "myBA1" & vbCrLf
      outputBlock.Text += String.Format("   Count:    {0}", myBA1.Count) & vbCrLf
      outputBlock.Text += String.Format("   Length:   {0}", myBA1.Length) & vbCrLf
      outputBlock.Text &= "   Values:" & vbCrLf
      PrintValues(outputBlock, myBA1, 8)

      outputBlock.Text &= "myBA2" & vbCrLf
      outputBlock.Text += String.Format("   Count:    {0}", myBA2.Count) & vbCrLf
      outputBlock.Text += String.Format("   Length:   {0}", myBA2.Length) & vbCrLf
      outputBlock.Text &= "   Values:" & vbCrLf
      PrintValues(outputBlock, myBA2, 8)

      outputBlock.Text &= "myBA3" & vbCrLf
      outputBlock.Text += String.Format("   Count:    {0}", myBA3.Count) & vbCrLf
      outputBlock.Text += String.Format("   Length:   {0}", myBA3.Length) & vbCrLf
      outputBlock.Text &= "   Values:" & vbCrLf
      PrintValues(outputBlock, myBA3, 8)

      outputBlock.Text &= "myBA4" & vbCrLf
      outputBlock.Text += String.Format("   Count:    {0}", myBA4.Count) & vbCrLf
      outputBlock.Text += String.Format("   Length:   {0}", myBA4.Length) & vbCrLf
      outputBlock.Text &= "   Values:" & vbCrLf
      PrintValues(outputBlock, myBA4, 8)

      outputBlock.Text &= "myBA5" & vbCrLf
      outputBlock.Text += String.Format("   Count:    {0}", myBA5.Count) & vbCrLf
      outputBlock.Text += String.Format("   Length:   {0}", myBA5.Length) & vbCrLf
      outputBlock.Text &= "   Values:" & vbCrLf
      PrintValues(outputBlock, myBA5, 8)

   End Sub 'Main

   Public Shared Sub PrintValues(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal myList As IEnumerable, ByVal myWidth As Integer)
      Dim i As Integer = myWidth
      Dim obj As [Object]
      For Each obj In myList
         If i <= 0 Then
            i = myWidth
            outputBlock.Text &= vbCrLf
         End If
         i -= 1
         outputBlock.Text += String.Format("{0,8}", obj)
      Next obj
      outputBlock.Text &= vbCrLf
   End Sub 'PrintValues

End Class 'SamplesBitArray 


' This code produces the following output.
' 
' myBA1
'    Count:    5
'    Length:   5
'    Values:
'    False   False   False   False   False
' myBA2
'    Count:    5
'    Length:   5
'    Values:
'    False   False   False   False   False
' myBA3
'    Count:    40
'    Length:   40
'    Values:
'     True   False   False   False   False   False   False   False
'    False    True   False   False   False   False   False   False
'     True    True   False   False   False   False   False   False
'    False   False    True   False   False   False   False   False
'     True   False    True   False   False   False   False   False
' myBA4
'    Count:    5
'    Length:   5
'    Values:
'     True   False    True    True   False
' myBA5
'    Count:    160
'    Length:   160
'    Values:
'    False    True    True   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'     True    True    True   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False    True   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'     True   False   False    True   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False    True   False    True   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False
'    False   False   False   False   False   False   False   False



Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

This implementation does not provide a synchronized (thread safe) wrapper for a BitArray.

Enumerating through a collection is intrinsically not a thread-safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

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