Add DispatcherTimer to the list of available timer classes

[softworkz]

This is just meant to be a hint.
Why is there's no feedback section at the bottom?

Feel free to close this and do it in a better way.

[gewarren]

Thanks for adding this. The feedback section was removed from the API ref docs simply because we could not answer every issue in a timely fashion.

[softworkz]

All changes are fine for me!

[softworkz]

The feedback section was removed from the API ref docs simply because we could not answer every issue in a timely fashion.

That's unfortunate, I really liked it. Often just for reading the comments from other users..

I understand that there's a small edge for this getting misused as a support channel, but still - most of the questions I read - were still justified to be covered by the documentation to avoid those coming up as support questions..

[gewarren]

@kouvel Do you approve this PR?

[kouvel]

Makes sense to me but I don't have much background or context in that area. @stephentoub, who would know more about this?

[stephentoub]

I see that Windows Forms' counterpart is included already, so it seems fine to list WPF's as well.

[softworkz]

It was just that I had momentarily forgotten the name of DispatcherTimer and this "list of .NET timer classes" didn't help as it didn't include it.

But if I had known that it would allocate so many people's time, I wouldn't have submitted. Apologies..

[KalleOlaviNiemitalo]

There is a similar list of timer classes at System.Timers.Timer. It would be good to keep these synchronized:

dotnet-api-docs/xml/System.Timers/Timer.xml

Lines 85 to 91 in 50c98f5

	> [!TIP]
	> Be aware that .NET includes four classes named `Timer`, each of which offers different functionality:
	>
	> - <xref:System.Timers.Timer?displayProperty=nameWithType> (this topic): fires an event at regular intervals. The class is intended for use as a server-based or service component in a multithreaded environment; it has no user interface and is not visible at runtime.
	> - <xref:System.Threading.Timer?displayProperty=nameWithType>: executes a single callback method on a thread pool thread at regular intervals. The callback method is defined when the timer is instantiated and cannot be changed. Like the <xref:System.Timers.Timer?displayProperty=nameWithType> class, this class is intended for use as a server-based or service component in a multithreaded environment; it has no user interface and is not visible at runtime.
	> - <xref:System.Windows.Forms.Timer?displayProperty=nameWithType> (.NET Framework only): a Windows Forms component that fires an event at regular intervals. The component has no user interface and is designed for use in a single-threaded environment.
	> - <xref:System.Web.UI.Timer?displayProperty=nameWithType> (.NET Framework only): an ASP.NET component that performs asynchronous or synchronous web page postbacks at a regular interval.

That list seems to be out of date already, as System.Windows.Forms.Timer is available on .NET Core 3.0 and later.

I suppose the "this topic" self-reference prevents !INCLUDE from being used.

[gewarren]

@KalleOlaviNiemitalo Good point. Would you like to create a new PR for System.Timers.Timer?

[KalleOlaviNiemitalo]

No, I wouldn't.