Trouble with my timer

Question

I am trying to make a timer that triggers a method, that updates a text box that acts as a clock, every minute so that each minute that passes in real life is an hour in game. Here is the code I have so far:

public partial class Terminal : Form
{
    static int time;
    System.Timers.Timer timer1 = new System.Timers.Timer();

    private void Terminal_Load(object sender, EventArgs e)
    {
        time = 0;

        timer1.Elapsed += new ElapsedEventHandler(UpdateTime);
        timer1.Interval = 1000;
        timer1.AutoReset = true;

        GoToPage(Pages.Tasks);
        UpdateClock(time);
        timer1.Start();
    } //private void Terminal_Load(object sender, EventArgs e)

    private void UpdateTime(object source, ElapsedEventArgs eea)
    {
        if (time < 6) //the clock is not supposed to go any further than 6 am
            time++;
        UpdateClock(time);
    } //private static Task UpdateTime(int t)

    private void UpdateClock(int t)
    {
        if (time == 0)
        {
            timeBox.Text = "12 AM";
        } //if
        else if (time > 0 && time <= 6)
        {
            timeBox.Text = time + " AM"; //error appears here each time the timer elapses
        } //else if
    } //private void UpdateClock()
} //public partial class Terminal : Form

But I keep on getting this error at the above specified line:

"An exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll but was not handled in user code

Additional information: Cross-thread operation not valid: Control 'timeBox' accessed from a thread other than the thread it was created on."

If anyone could help me out that would be great

You have to set 'timeBox.Text' in the GUI Thread. As explained here: https://stackoverflow.com/questions/6268250/begininvoke-gui-and-thread — richej, Dec 12 '17 at 09:15
Possible duplicate of [Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on](https://stackoverflow.com/questions/142003/cross-thread-operation-not-valid-control-accessed-from-a-thread-other-than-the) — Equalsk, Dec 12 '17 at 09:17

Mong Zhu · Accepted Answer · 2017-12-12T09:49:05.433

You problem comes from the point that the event is fired on a different thread than the user interface (UI) is running on. All the control elements of the UI belong to the UI-thread and the system will not allow you to manipulate them from another thread.

It looks like you are working in WinForms, so I would suggest to take the Timer supplied by the namespace System.Windows.Forms. It runs on the UI-Thread so this exception will disappear and no need to use Invoke:

System.Windows.Forms.Timer timer1 = new System.Windows.Forms.Timer();

the event is here called Tick instead of Elapsed:

timer1.Tick += UpdateTime;

Your method will look a little different:

private void UpdateTime(object sender, EventArgs e)
{

this timer will also restart automatically until you call Stop() on the timer

Trouble with my timer

1 Answers1