Export (0) Print
Expand All

SortedList.IsSynchronized Property

Gets a value indicating whether access to a SortedList object is synchronized (thread safe).

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

Public Overridable ReadOnly Property IsSynchronized As Boolean

Property Value

Type: System.Boolean
true if access to the SortedList object is synchronized (thread safe); otherwise, false. The default is false.



To guarantee the thread safety of a SortedList object, all operations must be done through the wrapper returned by the Synchronized method.

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.

The following code example shows how to lock a collection using the SyncRoot property during the entire enumeration.

Dim myCollection As New SortedList()
SyncLock myCollection.SyncRoot
    For Each item In myCollection
        ' Insert your code here. 
    Next item
End SyncLock

Retrieving the value of this property is an O(1) operation.

The following code example shows how to synchronize a SortedList object, determine whether a SortedList is synchronized, and use a synchronized SortedList.

Imports System
Imports System.Collections
Imports Microsoft.VisualBasic

Public Class SamplesSortedList

    Public Shared Sub Main()

        ' Creates and initializes a new SortedList. 
        Dim mySL As New SortedList()
        mySL.Add(2, "two")
        mySL.Add(3, "three")
        mySL.Add(1, "one")
        mySL.Add(0, "zero")
        mySL.Add(4, "four")

        ' Creates a synchronized wrapper around the SortedList. 
        Dim mySyncdSL As SortedList = SortedList.Synchronized(mySL)

        ' Displays the sychronization status of both SortedLists. 
        Dim msg As String 
        If mySL.IsSynchronized Then
            msg = "synchronized" 
            msg = "not synchronized" 
        End If
        Console.WriteLine("mySL is {0}.", msg)
        If mySyncdSL.IsSynchronized Then
            msg = "synchronized" 
            msg = "not synchronized" 
        End If
        Console.WriteLine("mySyncdSL is {0}.", msg)        
    End Sub 
End Class 

' This code produces the following output. 

' mySL is not synchronized. 
' mySyncdSL is synchronized.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, 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.

© 2014 Microsoft