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Lazy(Of T).IsValueCreated Property

Gets a value that indicates whether a value has been created for this Lazy(Of T) instance.

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

'Declaration
Public ReadOnly Property IsValueCreated As Boolean

Property Value

Type: System.Boolean
true if a value has been created for this Lazy(Of T) instance; otherwise, false.

When lazy initialization occurs for a Lazy(Of T) instance, it may result in either a value being created or an exception being thrown. If an exception is thrown, subsequent behavior of the Lazy(Of T) instance depends on whether exception caching is in effect. If the Lazy(Of T) instance was created by using a constructor that does not specify an initialization function, then exception caching is not in effect. A subsequent attempt to initialize the Lazy(Of T) might succeed, and after successful initialization the IsValueCreated property returns true. If the Lazy(Of T) instance was created with an initialization function (specified by the valueFactory parameter of the Lazy(Of T) constructor), then exception caching is controlled by the thread safety mode.

  • If the mode is LazyThreadSafetyMode.ExecutionAndPublication or LazyThreadSafetyMode.None, there is no second chance to initialize the Lazy(Of T) instance. If an exception occurs and is unhandled in the initialization function, that exception is cached and rethrown on subsequent accesses of the Lazy(Of T).Value property. No value is created if an exception is thrown, so in such cases IsValueCreated returns false.

  • If the mode is LazyThreadSafetyMode.PublicationOnly, the first thread that succeeds in running the initialization function (or the default constructor) creates the value for the Lazy(Of T) instance. If the initialization function throws an exception on one thread, other threads can still try to initialize the Lazy(Of T) instance. Until the value is created, the IsValueCreated property returns false.

Silverlight

Supported in: 5, 4

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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