Wait some seconds without blocking UI execution

Solution 1:

I think what you are after is Task.Delay. This doesn't block the thread like Sleep does and it means you can do this using a single thread using the async programming model.

async Task PutTaskDelay()
{
    await Task.Delay(5000);
} 

private async void btnTaskDelay_Click(object sender, EventArgs e)
{
    await PutTaskDelay();
    MessageBox.Show("I am back");
}

Solution 2:

I use:

private void WaitNSeconds(int segundos)
{
    if (segundos < 1) return;
    DateTime _desired = DateTime.Now.AddSeconds(segundos);
    while (DateTime.Now < _desired) {
         System.Windows.Forms.Application.DoEvents();
    }
}

Solution 3:

This is a good case for using another thread:

// Call some method
this.Method();

Task.Factory.StartNew(() =>
{
    Thread.Sleep(20000);

    // Do things here.
    // NOTE: You may need to invoke this to your main thread depending on what you're doing
});

The above code expects .NET 4.0 or above, otherwise try:

ThreadPool.QueueUserWorkItem(new WaitCallback(delegate
{
    Thread.Sleep(20000);

    // Do things here
}));

Solution 4:

Omar's solution is decent* if you cannot upgrade your environment to .NET 4.5 in order to gain access to the async and await APIs. That said, there here is one important change that should be made in order to avoid poor performance. A slight delay should be added between calls to Application.DoEvents() in order to prevent excessive CPU usage. By adding

Thread.Sleep(1);

before the call to Application.DoEvents(), you can add such a delay (1 millisecond) and prevent the application from using all of the cpu cycles available to it.

private void WaitNSeconds(int seconds)
{
    if (seconds < 1) return;
    DateTime _desired = DateTime.Now.AddSeconds(seconds);
    while (DateTime.Now < _desired) {
         Thread.Sleep(1);
         System.Windows.Forms.Application.DoEvents();
    }
}

*See https://blog.codinghorror.com/is-doevents-evil/ for a more detailed discussion on the potential pitfalls of using Application.DoEvents().

Solution 5:

If you do not want to block things and also not want to use multi threading, here is the solution for you: https://msdn.microsoft.com/en-us/library/system.timers.timer(v=vs.110).aspx

The UI Thread is not blocked and the timer waits for 2 seconds before doing something.

Here is the code coming from the link above:

        // Create a timer with a two second interval.
    aTimer = new System.Timers.Timer(2000);
    // Hook up the Elapsed event for the timer. 
    aTimer.Elapsed += OnTimedEvent;
    aTimer.Enabled = true;

    Console.WriteLine("Press the Enter key to exit the program... ");
    Console.ReadLine();
    Console.WriteLine("Terminating the application...");