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DispatcherFrame Class

Represents an execution loop in the Dispatcher.

System.Object
  System.Windows.Threading.DispatcherObject
    System.Windows.Threading.DispatcherFrame

Namespace:  System.Windows.Threading
Assembly:  WindowsBase (in WindowsBase.dll)
XMLNS for XAML: Not mapped to an xmlns.

'Declaration
Public Class DispatcherFrame _
	Inherits DispatcherObject
You cannot use this managed class in XAML.

The DispatcherFrame type exposes the following members.

  NameDescription
Public methodDispatcherFrameInitializes a new instance of the DispatcherFrame class.
Public methodDispatcherFrame(Boolean)Initializes a new instance of the DispatcherFrame class, by using the specified exit request flag.
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  NameDescription
Public propertyContinueGets or sets a value that indicates whether this DispatcherFrame should continue.
Public propertyDispatcherGets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)
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  NameDescription
Public methodCheckAccessDetermines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodVerifyAccessEnforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
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DispatcherFrame objects typically fall into two categories:

  • Long running, general purpose frames that exit only when instructed to. These frames should exit when they are requested.

  • Short running, very specific frames that exit when an important criteria is met. These frames may consider not to exit when they are requested in favor of waiting for their exit criteria to be met. These frames should have a time-out associated with them.

The following example shows how to use a DispatcherFrame to achieve similar results as the Windows Forms DoEvents method.

		<SecurityPermissionAttribute(SecurityAction.Demand, Flags := SecurityPermissionFlag.UnmanagedCode)>
		Public Sub DoEvents()
			Dim frame As New DispatcherFrame()
			Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, New DispatcherOperationCallback(AddressOf ExitFrame), frame)
			Dispatcher.PushFrame(frame)
		End Sub

		Public Function ExitFrame(ByVal f As Object) As Object
			CType(f, DispatcherFrame).Continue = False

			Return Nothing
		End Function

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0

.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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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