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LazyInitializer Class

Provides lazy initialization routines.

System.Object
  System.Threading.LazyInitializer

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

[HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true, 
	ExternalThreading = true)]
public static class LazyInitializer

  NameDescription
Public methodStatic memberEnsureInitialized<T>(T)Initializes a target reference type with the type's default constructor if the target has not already been initialized.
Public methodStatic memberEnsureInitialized<T>(T, Func<T>)Initializes a target reference type using the specified function if it has not already been initialized.
Public methodStatic memberEnsureInitialized<T>(T, Boolean, Object)Initializes a target reference or value type with its default constructor if it has not already been initialized.
Public methodStatic memberEnsureInitialized<T>(T, Boolean, Object, Func<T>)Initializes a target reference or value type with a specified function if it has not already been initialized.
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These routines avoid needing to allocate a dedicated, lazy-initialization instance, instead using references to ensure targets have been initialized as they are accessed.

NoteNote

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: Synchronization | ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following example demonstrates how to use EnsureInitialized to lazily initialize a value using a Boolean value to track whether initialization has already happened and an object to use as the mutual exclusion lock.

ExpensiveData _data = null;
                     bool _dataInitialized = false;
                     object _dataLock = new object();
                  //  ...

                    ExpensiveData dataToUse = LazyInitializer.EnsureInitialized(ref _data, ref _dataInitialized, ref _dataLock);

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

The methods of LazyInitializer are thread-safe and may be called from multiple threads concurrently.

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