Add Timer to a Windows Forms Application

Add timer to a Windows Forms application

Bit more detail:

    private void Form1_Load(object sender, EventArgs e)
    {
        Timer MyTimer = new Timer();
        MyTimer.Interval = (45 * 60 * 1000); // 45 mins
        MyTimer.Tick += new EventHandler(MyTimer_Tick);
        MyTimer.Start();
    }

    private void MyTimer_Tick(object sender, EventArgs e)
    {
        MessageBox.Show("The form will now be closed.", "Time Elapsed");
        this.Close();
    }

Using timer in windows form application

Adding a new event handler to a timer, to handle its tick event, inside the handler for the tick event will indeed cause the timer to go "crazy". Every time the timer raises its event, another event handler (that responds to events raised) will be added. This means the next time the timer ticks, the event code will run twice. Two new event handlers will be added. Next time the timer ticks, the code will run 4 times. 4 event handlers will be added ... and so on

Remove this line from your code:

timer.Tick += new EventHandler(Scatter_modeToolStripMenuItem_Click);

And move this line into your form's constructor:

timer.Tick += new EventHandler(Dosomething);

You only want to wire this event handler up once. Every time the timer's interval elapses, the code will run, once :)

I'll also do a bit of a peer review of your code, see the comments:

 System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();

//ScatterMode Tab
private void Scatter_modeToolStripMenuItem_Click(object sender, EventArgs e)
{
        timer.Interval = 4000; //can go in the constructor also; don't need to set repeatedly
        timer.Enabled = true;
        timer.Tick += new EventHandler(Dosomething); //move to constructor
        timer.Start(); //this isn't needed - you already Enabled the timer, which started it
}

private void Dosomething (object sender, EventArgs e)
{
    timer.Stop();          //use this
    timer.Enabled = false; //or this. It's not required to do both

    Grab.buffer(out buffer, out status, 6000);  //if these lines crash then your timer will
    Scatter_mode(buffer);                       //only restart if the toolstripmenuitemclick
    pictureBox1.Refresh();                      //above runs.. is it what you wanted?

    int done_grab = 1; //not needed

    if (doneGrab == 1) //this will always evaluate to true, it is not needed
    {
        timer.Interval = 4000; //the interval is already 4000, not needed
        timer.Enabled = true; //careful; your timer may stop forever if the code above crashes
        timer.Tick += new EventHandler(Scatter_modeToolStripMenuItem_Click); //remove
        timer.Start(); //not needed
        done_grab = 0; //not needed
    }
}

Timer firing every second and updating GUI (C# Windows Forms)

A timer needs to be declared at the form level, or else it may not be disposed of when the form closes:

System.Windows.Forms.Timer timer;
int counter = 0;

Your starting code should just start the timer:

private void ScanpXRF()
{
   counter = 0;
   timer = new System.Windows.Forms.Timer();
   timer.Interval = 1000;
   timer.Tick += RunEvent;
   timer.Start();
}

The RunEvent is your Tick event being called every second, so your logic needs to go in there:

private void RunEvent(object sender, EventArgs e)
{
  counter++;
  if (counter >= 90) {
    timer.Stop();
    // do something...
  }
}

How can i start timer immediately in windows form?

Edit
I know your question is "how to start the timers immediately", but in your code they are starting immediately. When you call start the timer starts. I believe the effect you are seeing is related to the delay associated with the tick event, which from the description I am assuming is set to a 1 second interval. Since you have said that you are trying to simulate something similar to a chess timer (although in your case counting up as opposed to down), then using something like a stop watch which can start, stop and show elapsed time would be a closer model. Since there is a Stopwatch class that provides exactly this behavior, I think it would be easier to implement it using two of those and just have a single background thread that updates the UI as frequently as needed. You could even add an update call into each button push to ensure the text boxes are up to date.

===============================

Maybe instead of the timers you should use two instances of the Stopwatch class. This will remove the need for your two variables that you are using to keep track of the seconds as the Stopwatch class will be holding the elapsed time for each counter.

Then in your button methods you could just do this:

private Stopwatch sw1 = new Stopwatch();
private Stopwatch sw2 = new Stopwatch();

    private void button1_Click(object sender , EventArgs e) {
        sw1.Start();
        sw2.Stop();
    }
    private void button2_Click(object sender , EventArgs e) {
        sw2.Start();
        sw1.Stop();
    }

And then you can use a Background worker or some other background thread that runs and updates your text boxes with the elapsed time from the timers you just need to grab the elapsed time.

// This will give you the total number of seconds elapsed.
var timer1Seconds = Math.Floor(sw1.Elapsed.TotalSeconds);

Here is an example of how you can make this update the UI:

    private bool _stop = false;
    public Form1()
    {
        InitializeComponent();

        Task.Run(() =>
        {
            while(!_stop)
            {
                UpdateElapsedTimes();
                Thread.Sleep(1000);
            }
        }
    }

    private void UpdateElapsedTimes()
    {
        if (InvokeRequired)
        {
            Invoke(UpdateElapsedTimes());
            return;
        }

        label1.Text = Math.Floor(sw1.Elapsed.TotalSeconds).ToString();
        label2.Text = Math.Floor(sw2.Elapsed.TotalSeconds).ToString();
    }

Note - in a production program I would not use a boolean as my loop checker, you would use an event handle, and probably a couple of event handles if you wanted to allow pausing the updates, this is just to show an idea of how to do it. You could invoke directly from the thread method and drop the InvokeRequired check, but I added that for additional safety and since it was there I skipped it in the loop.

How to add a timer to a dynamic created labels in a winform C#?

You can use this:

private Dictionary<Timer, DateTime> Timers = new Dictionary<Timer, DateTime>();

public Form1()
{
  InitializeComponent();

  var p = new Panel();
  p.Size = new Size(360, 500);
  p.BorderStyle = BorderStyle.FixedSingle;
  p.Name = "panel";
  Controls.Add(p);

  var tpanel = new TableLayoutPanel();
  tpanel.Name = "tablepanel";
  tpanel.Controls.Add(new ListBox() { Text = "qtylistBox2" }, 1, 3);
  p.Controls.Add(tpanel);

  Action<string, int, int> createLabel = (text, x, y) =>
  {
    var label = new Label();
    label.Text = text;
    tpanel.Controls.Add(label, x, y);
    var timer = new Timer();
    timer.Interval = 1000;
    timer.Tick += (sender, e) => 
    {
      label.Text = DateTime.Now.Subtract(Timers[sender as Timer]).ToString("mm\\:ss");
    };
    Timers.Add(timer, DateTime.Now);
  };

  // create one label
  createLabel("0", 2, 1);

  // create other label
  // createLabel("", 0, 0);

  foreach ( var item in Timers )
    item.Key.Enabled = true;
}

C# Windows Form Countdown Timer

You need to do two things to get it working:

You need to start the timer in startbutton_Click:

if (hours >= 1 || (minutes >= 1) || (seconds >= 1))

//If there is at least one integer entered in any of the 3 boxes, executes; else - //throws an exception
{
    startbutton.Enabled = true;
    ...
    timer1.Enabled = true;
}

You need to hook up the timer Tick event to timer1_Tick. You can do this by selecting the timer and clicking on the lightning bolt toolbar icon on the Properties frame, then selecting timer1_Tick for Tick.

---

Related Topics