Question

I have a Game in which there is a timer involved. For each two minutes that passes a new round between different players begins. So, I have a text box starting from 00:00 and changes each second until it is equal to 02:00.

Now, I want to save the state of the game in the middle of a round if the user closes the form. What I need to do is that upon loading, the textbox starts at the time that the user left the game the last time and continue up till 02:00 normally.

How can I do this?

This is what I have until now where Tournament is the Form

public Tournament()
{
     _timer = new System.Windows.Forms.Timer();
     _timer.Interval = 1000;
     _timer.Tick += Timer_Tick;
     _myDateTime = DateTime.Now;
     newDate = new DateTime();
     newDate = newDate.AddMinutes(2.00);
     _timer.Start();
     InitializeComponent();
}

void Timer_Tick(object sender, EventArgs e)
{
     var diff = DateTime.Now.Subtract(_myDateTime);
     this.textBox1.Text = diff.ToString(@"mm\:ss");

     DateTime dt = Convert.ToDateTime(diff.ToString());

     if (newDate.Minute == dt.Minute)
     {
         _timer.Stop();
         _myDateTime = DateTime.Now;

         displayPointsOrResults();

         this.textBox1.Text = diff.ToString(@"mm\:ss");  
     }
   }

In my LoadGame method: where timePassed is what I have written in the text box

  string[] splitted6 = timePassed.Split(':');

  if (splitted6[0] == "00")
  {
      int remainingTime = 120 - Convert.ToInt32(splitted6[1]);

      DateTime time = DateTime.Now.Date; 
      time = time.AddMinutes(remainingTime);

      _myDateTime = time;
  }
  else
  {
      int leftTime = Convert.ToInt32(splitted[0].Trim('0') + splitted[1]);
      int remainingTime = 120 - leftTime;

      DateTime time = DateTime.Now.Date; 
      time = time.AddMinutes(remainingTime);

      _myDateTime = time;
  } 

Answer 1

Use TimeSpan instead of DateTime to save and load current timeout:

int _roundDuration = 2 * 60; // 2 minutes

void Timer_Tick(object sender, EventArgs e)
{
     TimeSpan diff = DateTime.Now - _myDateTime;
     textBox1.Text = diff.ToString(@"mm\:ss");
     if (diff.TotalSeconds >= _roundDuration)
     {
          _timer.Stop();    
          _myDateTime = DateTime.Now;
          displayPointsOrResults();
     }
}

When loading game (parsing textBox1.Text):

TimeSpan diff = TimeSpan.ParseExact(textBox1.Text, @"mm\:ss", null);
_myDateTime = DateTime.Now.Substract(diff);

Whenever you load game, start time will be calculated as it was started displayed timeout ago.