SortedList::Synchronized Method (SortedList^)


Returns a synchronized (thread-safe) wrapper for a SortedList object.

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

[HostProtectionAttribute(SecurityAction::LinkDemand, Synchronization = true)]
static SortedList^ Synchronized(
	SortedList^ list


Type: System.Collections::SortedList^

The SortedList object to synchronize.

Return Value

Type: System.Collections::SortedList^

A synchronized (thread-safe) wrapper for the SortedList object.

Exception Condition

list is null.

To guarantee the thread safety of a SortedList object, all operations must be done through this wrapper only.

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.

SortedList^ myCollection = gcnew SortedList();
bool lockTaken = false;
    Monitor::Enter(myCollection->SyncRoot, lockTaken);
    for each (Object^ item in myCollection);
        // Insert your code here.
    if (lockTaken)

This method 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.

#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()

   // Creates and initializes a new SortedList.
   SortedList^ mySL = gcnew SortedList;
   mySL->Add( 2, "two" );
   mySL->Add( 3, "three" );
   mySL->Add( 1, "one" );
   mySL->Add( (int^)0, "zero" );
   mySL->Add( 4, "four" );

   // Creates a synchronized wrapper around the SortedList.
   SortedList^ mySyncdSL = SortedList::Synchronized( mySL );

   // Displays the sychronization status of both SortedLists.
   Console::WriteLine( "mySL is {0}.", mySL->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
   Console::WriteLine( "mySyncdSL is {0}.", mySyncdSL->IsSynchronized ? (String^)"synchronized" : "not synchronized" );

This code produces the following output.

mySL is not synchronized.
mySyncdSL is synchronized.

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
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