How to make a Time Left Countdown List

Question

I am making a countdown list where each item contains a datetime to count down to and each listview datatemplate needs to show this countdown in real time. What is the best and most optimized way to make a list that counts down to a specified time using a SfListView?

Thanks,

Bryson

Sowntharya Jayamoorthy · Answer

Hi Bryson,We have prepared a sample demonstrating a time left countdown list implementation using SfListView control, which you can review in the attached reference. This solution showcases dynamic countdown tracking with real-time updates. Please let us know if you need further assistance. public class CountdownItem : INotifyPropertyChanged { // Gets or sets the target date and time for the countdown public DateTime TargetDateTime { get; set; } // Gets or sets the display name for the target duration public string? TargetTime { get; set; } // Gets or sets the remaining time display value. // Triggers PropertyChanged event on update. private string? remainingTime; public string? RemainingTime { get { return remainingTime; } set { remainingTime = value; OnPropertyChanged(nameof(RemainingTime)); } } } public class CountdownViewModel : INotifyPropertyChanged { public ObservableCollection CountdownItems { get; set; } private System.Timers.Timer timer; public CountdownViewModel() { // Initializes countdown items and starts the update timer CountdownItems = new ObservableCollection { new CountdownItem { TargetTime="10 Seconds", TargetDateTime = DateTime.Now.AddSeconds(10) },// Countdown for 10 seconds new CountdownItem { TargetTime="5 Minutes", TargetDateTime = DateTime.Now.AddMinutes(5) }, // Countdown for 5 minutes new CountdownItem { TargetTime="10 Minutes", TargetDateTime = DateTime.Now.AddMinutes(10) }, // Countdown for 10 minutes new CountdownItem { TargetTime="1 Hour", TargetDateTime = DateTime.Now.AddHours(1) }, // Countdown for 1 hour new CountdownItem { TargetTime="1 Day", TargetDateTime = DateTime.Now.AddDays(1) } // Countdown for 1 day }; StartTimer(); } private void StartTimer() { timer = new System.Timers.Timer(1000); // 1 second interval timer.Elapsed += TimerElapsed; // start a timer timer.Start(); } // Timer callback that updates all countdown items' remaining times private void TimerElapsed(object sender, ElapsedEventArgs e) { foreach (var item in CountdownItems) { // calculate remaining time TimeSpan timeLeft = item.TargetDateTime - DateTime.Now; item.RemainingTime = timeLeft > TimeSpan.Zero ? timeLeft.ToString(@"hh\:mm\:ss") : "Time's up!"; } } } Displays countdowns in a ListView: Regards,Sowntharya J.