Start countdown at a specific time and show it in a label-CodePudding

I have this event that is running every minute.

void checkForTime_Elapsed(object sender, ElapsedEventArgs e)
{
    if (DateTime.Now.Hour == 10 && DateTime.Now.Minute == 35)
    {
        tik_tak();
    }
}

And at a specific time, in my case 10:35 I want to display a countdown timer in a label (I already have)

    private void tik_tak()
    {
        EndOfTime = DateTime.Now.AddMinutes(10);
        System.Windows.Forms.Timer t = new System.Windows.Forms.Timer() { Interval = 500, Enabled = true };
        t.Tick  = new EventHandler(t_Tick);
        t_Tick(null, null);
    }

    void t_Tick(object sender, EventArgs e)
    {
        TimeSpan ts = EndOfTime.Subtract(DateTime.Now);
        label1.Text = ts.ToString();
    }

And now I am getting "Cross-thread operation not valid: Control 'label1' accessed from a thread other than the thread it was created on"

How can I manage to do this?

CodePudding user response：

You can't modify your GUI elements from another thread. For do this you need to instruct your dispacther to execute this line of code label1.Text = ts.ToString(); on its thread.

It is done in this way

label1.BeginInvoke((MethodInvoker)delegate ()
            {
                label1.Text = ts.ToString();
            });