DispatcherObject.VerifyAccess Method

Definition

Namespace:

System.Windows.Threading

Assembly:

WindowsBase.dll

Enforces that the calling thread has access to this DispatcherObject.

public:
 void VerifyAccess();

public void VerifyAccess ();

member this.VerifyAccess : unit -> unit

Public Sub VerifyAccess ()

Exceptions

InvalidOperationException

the calling thread does not have access to this DispatcherObject.

Examples

The following example uses VerifyAccess to determine whether a thread has access to the thread that a Button was created on. If the calling thread does not have access, an InvalidOperationException is thrown.

// Check if this thread has access to this object.
theButton.VerifyAccess();

// Thread has access to the object, so update the UI.
UpdateButtonUI(theButton);

' Check if this thread has access to this object.
theButton.VerifyAccess()

' Thread has access to the object, so update the UI.
UpdateButtonUI(theButton)

Remarks

Only the thread the Dispatcher was created on may access the DispatcherObject.

Any thread can check to see whether it has access to this DispatcherObject.

The difference between CheckAccess and VerifyAccess is that CheckAccess returns a Boolean that specifies whether the calling thread has access to this DispatcherObject and VerifyAccess throws an exception if the calling thread does not have access to the this DispatcherObject.