Private ReadOnly Property SyncRoot As Object
    Implements ICollection.SyncRoot

Dim instance As ReadOnlyCollectionBase
Dim value As Object

value = CType(instance, ICollection).SyncRoot

Object ICollection.SyncRoot { get; }

private:
virtual property Object^ SyncRoot {
    Object^ get () sealed = ICollection::SyncRoot::get;
}

JScript does not support explicit interface implementations.

Implements

Derived classes can provide their own synchronized version of the ReadOnlyCollectionBase class using the SyncRoot property. The synchronizing code must perform operations on the SyncRoot property of the ReadOnlyCollectionBase object, not directly on the ReadOnlyCollectionBase object. 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 ReadOnlyCollectionBase 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 property during the entire enumeration.

ReadOnlyCollectionBase myCollection = new ReadOnlyCollectionBase();
  lock(myCollection.SyncRoot) {
  foreach (Object item in myCollection) {
  // Insert your code here.
  }
 }

Dim myCollection As New ReadOnlyCollectionBase()
 Dim item As Object
 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.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework

Reference