SynchronizingObject for an event

Question

With Timer objects, I can set the SynchronizingObject property to avoid having to use invoke when updating the GUI from the timer's event handler. If I have a class that instead subscribes to an event and has to update the GUI in the event handler, is there an analogous concept? Or do I have to write the InvokeRequired boilerplate code?

Jazminejazz

Answer 1

SynchronizingObject is just an ISynchronizeInvoke property. (That interface is implemented by WinForms controls, for example.)

You can use the same interface yourself, although with a vanilla event there's nowhere to really specify the synchronization object.

What you could do is write a utility method which takes a delegate and an ISynchronizeInvoke, and returns a delegate which makes sure the original delegate is run on the right thread.

For example:

public static EventHandler<T> Wrap<T>(EventHandler<T> original,
    ISynchronizeInvoke synchronizingObject) where T : EventArgs
{
    return (object sender, T args) =>
    {
        if (synchronizingObject.InvokeRequired)
        {
            synchronizingObject.Invoke(original, new object[] { sender, args });
        }
        else
        {
            original(sender, args);
        }
    };
}

Earthaearthborn

Is this class appropriate to use when I want to synchronize with a self-defined class (not winforms) as shown here: https://mcmap.net/q/912450/-will-the-threadpool-queue-a-timer-39-s-callback-function-sometimes-scheduling-more-than-one-thread-at-the-same-time/328397 – Okie

@makerofthings7: I don't think it's the approach I'd use in that case, no. If you're using .NET 4, look at what the TPL provides. – Earthaearthborn

Answer 2

You may take a look at the BackgroundWorker class.

Kist