How to stop a timer/change system UI OnSleep Xamarin Android

» chash » How to stop a timer/change system UI OnSleep Xamarin Android

By : Tim Casey

Date : November 27 2020, 04:01 AM

this will help Just can see the partial code,you should check if your timer is initialized before executing the method.
When you do not click the start button, you need to check whether the timer is initialized, in order to perform the following timer operation.

code :

MessagingCenter.Subscribe<App>(this, "OnSleep", (sender) => {
//shows start button instead of stop button
if (null != timer)
{
    StartGrid.IsVisible = true;
    //hides stop button
    StopNextGrid.IsVisible = false;
    //stops timer
    timer.Stop();
    timer = null;
    //stops sound
    startSound.Stop();
    stopSound.Play();
}
});

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System.Timers.Timer Elapsed event executing after timer.Stop() is called

By : bala

Date : March 29 2020, 07:55 AM

it helps some times This is well known behavior. System.Timers.Timer internally uses ThreadPool for execution. Runtime will queue the Timer in threadpool. It would have already queued before you have called Stop method. It will fire at the elapsed time.
To avoid this happening set Timer.AutoReset to false and start the timer back in the elapsed handler if you need one. Setting AutoReset false makes timer to fire only once, so in order to get timer fired on interval manually start timer again.

code :

yourTimer.AutoReset = false;

private void Timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
     try
     {
         // add your logic here
     }
     finally
     {
         yourTimer.Enabled = true;// or yourTimer.Start();
     }
}

Xamarin.Forms 2.1.0.6521 - UWP Not Hitting OnStart / OnSleep methods

By : Satyam Gupta

Date : March 29 2020, 07:55 AM

Does that help Same problem found in the version of the library Xamarin.Form V2.0.0.6482. After updating the package Nuget in version V2.3.0.46 pre3, the problem is solved.

Which is to use Stop/Start timer vs SynchronizingObject vs lock for System.Timers.Timer?

By : Trevor Ochocki

Date : March 29 2020, 07:55 AM

I wish did fix the issue.
The 4th solution (lock) is a dangerous one. Since the Elapsed event will be raised on a ThreadPool thread each time and you might potentially block many of them simultaneously, this could cause the ThreadPool to grow (with all the consequences). So that solution is a bad one.

Popping the navigation stack from App.OnSleep in iOS in Xamarin Forms

By : Anirudh

Date : March 29 2020, 07:55 AM

seems to work fine I made 2 changes that seem to have made this work. I don't know which, but that's ok. I used the page's Navigation property and removed the Wait() call on PopAsync(). Could this cause timing issues where the pop doesn't complete before the app goes to sleep? Maybe that's a question for another day.

code :

var currentPage = this.MainPage as NavigationPage; // MainPage = new NavigationPage(new MainPage())
if (currentPage != null && currentPage.CurrentPage is FooPage)
{
    // FooPage was shown from MainPage with Navigation.PushAsync(new FooPage())
    currentPage.Navigation.PopAsync();
}

When I am navigating to a new Xamarin Page, content isnt displaying when I am running System.Timer.Timer code

By : user3128493

Date : March 29 2020, 07:55 AM

I wish this helpful for you I have updated my code. The Device.BeginInvokeOnMainThread you tried before, could solve your problem. Maybe you try the wrong way. You could refer to the code below.

code :

void t_Tick(object sender, EventArgs e)
    {
        Device.BeginInvokeOnMainThread(() =>
        {
            try
            {
                TimeSpan ts = endTime - DateTime.Now;
                string NewTimer = ts.ToString("d' Days 'h' Hours 'm' Minutes 's' Seconds'");
                lblCountDown.Text = NewTimer;
                if ((ts.TotalMilliseconds < 0) || (ts.TotalMilliseconds < 1000))
                {
                    timer.Stop();
                    lblCountDown.Text = "The day has arrived";
                }
            }
            catch (Exception ex)
            {
                string Error = ex.Message;
            }
        });

    }