c# - How can I cancel from Device.StartTimer? -

when use system.threading.timer can stop timer , start again:

protected override void onscrollchanged(int l, int t, int oldl, int oldt) {     if (timer == null)     {         system.threading.timercallback tcb = onscrollfinished;         timer = new system.threading.timer(tcb, null, 700, system.threading.timeout.infinite);     }     else     {         timer.change(system.threading.timeout.infinite, system.threading.timeout.infinite);         timer.change(700, system.threading.timeout.infinite);     } } 

what best way stop device.starttimer , start again?

i guessing referring device.starttime in xamarinforms. way stop or continue recurring task determined second argument returns:

// run task in 2 minutes device.starttimer(timespan.fromminutes(2), () => {     if (needstorecur)     {         // returning true fire task again in 2 minutes.         return true;     }      // no longer need recur. stops firing task     return false;  }); 

if want temporarily stop timer, , fire again after time, have call device.starttimer again. nice wrap own class can use private member determine if continuous task still running. this:

public class devicetimer {   readonly action _task;   readonly list<taskwrapper> _tasks = new list<taskwrapper>();   readonly timespan _interval;   public bool isrecurring { get; }   public bool isrunning => _tasks.any(t => t.isrunning);    public devicetimer(action task, timespan interval,      bool isrecurring = false, bool start = false)   {     _task = task;     _interval = interval;     isrecurring = isrecurring;     if (start)       start();   }    public void restart()   {     stop();     start();   }    public void start()   {     if (isrunning)       // running       return;      var wrapper = new taskwrapper(_task, isrecurring, true);     _tasks.add(wrapper);      device.starttimer(_interval, wrapper.runtask);   }    public void stop()   {     foreach (var task in _tasks)       task.isrunning = false;     _tasks.clear();   }     class taskwrapper   {     public bool isrunning { get; set; }     bool _isrecurring;     action _task;     public taskwrapper(action task, bool isrecurring, bool isrunning)     {       _task = task;       _isrecurring = isrecurring;       isrunning = isrunning;     }      public bool runtask()     {       if (isrunning)       {         _task();         if (_isrecurring)           return true;       }        // no longer need recur. stop       return isrunning = false;     }   }          }