Why are there 5 versions of timer classes in .NET?

Question

Why there are five classes of timers in the .Net Framework, namely:

1. System.Timers.Timer
2. System.Threading.Timer
3. System.Windows.Forms.Timer
4. System.Web.UI.Timer
5. System.Windows.Threading.DispatcherTimer

Why are there several versions of the Timer class? And how do they differ?

Answer 1

Here you go:

Comparing timer classes in the .NET Framework class library https://web.archive.org/web/20150329101415/https://msdn.microsoft.com/en-us/magazine/cc164015.aspx

Content

• System.Windows.Forms.Timer
• System.Timers.Timer
• System.Threading.Timer
• Timer programming with timers
• Work with the event register with a timer
• Conclusion

Answer 2

Timers.Timer generates an event after a specified interval with the ability to generate recurring events. MSDN

Windows.Forms.Timer is a control for winforms.

Web.UI.Timer performs asynchronous or synchronous Web.UI.Timer web page at a specific interval. MSDN

Threading.Timer - timer for callbacks. Creates a new theme for work. Served by thread pool threads. MSDN

So, these timers have different goals, and they are served by different tools.

Answer 3

Here is a description of the main timers and items that I find most noteworthy.

Winforms.Timer

• check marks in the user interface stream do not guarantee a ticket at a specific time
• ticks are delayed until the user interface thread is free
• will skip ticks if the UI thread is busy

DispatcherTimer

• invoked in a user interface thread
• you can set a priority for what level of "idle" is required to generate a tick
• will skip checkmarks

Threading.Timer

• marks a worker thread from a thread pool - there is no way to specify a thread
• ticks always shoot on time
• none of them are skipped - you should beware of new ticks while still processing the old tick

Timers.Timer

• Wrap around the stream timer
• marks on a workflow taken from the CLR thread pool
• can force a tick on a specific thread by providing a SynchronizationObject
• ticks always shoot on time
• none of them are missed
• silently eats exceptions