Class Dispatcher

Provides UI services for a thread.

Inheritance
object
Dispatcher
Inherited Members
Namespace: nanoFramework.UI.Threading
Assembly: nanoFramework.Graphics.dll
Syntax
public sealed class Dispatcher

Properties

CurrentDispatcher

Returns the Dispatcher for the current thread.

Declaration
public static Dispatcher CurrentDispatcher { get; }
Property Value
Type Description
Dispatcher

Dispatcher

HasShutdownFinished

Whether or not the dispatcher has been shut down.

Declaration
public bool HasShutdownFinished { get; }
Property Value
Type Description
bool

HasShutdownStarted

Whether or not the dispatcher is shutting down.

Declaration
public bool HasShutdownStarted { get; }
Property Value
Type Description
bool

Thread

Thread for the dispatcher.

Declaration
public Thread Thread { get; }
Property Value
Type Description
Thread

Methods

BeginInvoke(DispatcherOperationCallback, object)

Executes the specified delegate asynchronously with the specified arguments, on the thread that the Dispatcher was created on.

Declaration
public DispatcherOperation BeginInvoke(DispatcherOperationCallback method, object args)
Parameters
Type Name Description
DispatcherOperationCallback method

A delegate to a method that takes parameters of the same number and type that are contained in the args parameter.
object args

An object to pass as the argument to the given method. This can be null if no arguments are needed.
Returns
Type Description
DispatcherOperation

A DispatcherOperation object that represents the result of the BeginInvoke operation. null if the operation could not be queued.

CheckAccess()

Checks that the calling thread has access to this object.

Declaration
public bool CheckAccess()
Returns
Type Description
bool

True if the calling thread has access to this object.
Remarks

Only the dispatcher thread may access DispatcherObjects.

This method is public so that any thread can probe to see if it has access to the DispatcherObject.

FromThread(Thread)

Returns the Dispatcher for the specified thread.

Declaration
public static Dispatcher FromThread(Thread thread)
Parameters
Type Name Description
Thread thread
Returns
Type Description
Dispatcher
Remarks

If there is no dispatcher available for the specified thread, this method will return null.

Invoke(TimeSpan, DispatcherOperationCallback, object)

Executes the specified delegate synchronously with the specified arguments, on the thread that the Dispatcher was created on.

Declaration
public object Invoke(TimeSpan timeout, DispatcherOperationCallback method, object args)
Parameters
Type Name Description
TimeSpan timeout

The maximum amount of time to wait for the operation to complete.
DispatcherOperationCallback method

A delegate to a method that takes parameters of the same number and type that are contained in the args parameter.
object args

An object to pass as the argument to the given method. This can be null if no arguments are needed.
Returns
Type Description
object

The return value from the delegate being invoked, or null if the delegate has no return value or if the operation was aborted.

InvokeShutdown()

Begins the process of shutting down the dispatcher, synchronously. The process may complete asynchronously, since we may be nested in dispatcher frames.

Declaration
public void InvokeShutdown()

PushFrame(DispatcherFrame)

Push an execution frame.

Declaration
public static void PushFrame(DispatcherFrame frame)
Parameters
Type Name Description
DispatcherFrame frame

The frame for the dispatcher to process.

Run()

Push the main execution frame.

Declaration
public static void Run()
Remarks

This frame will continue until the dispatcher is shut down.

VerifyAccess()

Verifies that the calling thread has access to this object.

Declaration
public void VerifyAccess()
Remarks

Only the dispatcher thread may access DispatcherObjects.

This method is public so that derived classes can probe to see if the calling thread has access to itself.

Events

ShutdownFinished

Raised when the dispatcher is shut down.

Declaration
public event EventHandler ShutdownFinished
Event Type
Type Description
EventHandler

ShutdownStarted

Raised when the dispatcher starts shutting down.

Declaration
public event EventHandler ShutdownStarted
Event Type
Type Description
EventHandler

Extension Methods