Export (0) Print
Expand All

NameObjectCollectionBase.KeysCollection.ICollection.IsSynchronized Property

Gets a value indicating whether access to the NameObjectCollectionBase.KeysCollection is synchronized (thread safe).

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

bool ICollection.IsSynchronized { get; }

Property Value

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

Implements

ICollection.IsSynchronized

Derived classes can provide their own synchronized version of the NameObjectCollectionBase.KeysCollection using the SyncRoot property. The synchronizing code must perform operations on the SyncRoot of the NameObjectCollectionBase.KeysCollection, not directly on the NameObjectCollectionBase.KeysCollection. This ensures proper operation of collections that are derived from other objects. Specifically, it maintains proper synchronization with other threads that might be simultaneously modifying the NameObjectCollectionBase.KeysCollection object.

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 the collection using the SyncRoot during the entire enumeration.

// Create a collection derived from NameObjectCollectionBase
NameObjectCollectionBase myBaseCollection = new DerivedCollection();
// Get the ICollection from NameObjectCollectionBase.KeysCollection
ICollection myKeysCollection = myBaseCollection.Keys;
lock(myKeysCollection.SyncRoot)
{
    foreach (object item in myKeysCollection)
    {
        // Insert your code here.
    }
}

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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.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.

Show:
© 2014 Microsoft