Cross-thread operation not valid - used timer to do someting, but can't hide the form

[x9990860]

Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on.
[code=C#]
using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows. Forms;
using System.Timers;

namespace WindowsFormsApp lication2
{
public partial class Form1 : Form
{
private static System.Timers.T imer aTimer;

public Form1()
{
InitializeCompo nent();
aTimer = new System.Timers.T imer();
aTimer.Elapsed += new ElapsedEventHan dler(found_card );
// Set the Interval to 2 seconds.
aTimer.Interval = 1000;
aTimer.Enabled = true;

}

private void found_card(obje ct sender, EventArgs e)
{
aTimer.Enabled = false;

// use smart card system to find the card. if found the card, it will open form2 and close form1

Form form2 = new Form2();
this.Hide(); // <--- error, please help me to make a solution
form2.ShowDialo g();
this.Close();
}
}
}
[/code]

[Plater]

That exception only gets thrown in debug mode, to alert you of what you are doing.
In the exception message should be a link to MSDN about ways to solve that issue.
My favorite is using a delegate and invoke.

For instance in my form I have:
[code=c#]
private delegate string ReportInfoCallb ack(string msg);

private string ReportInfo(stri ng msg)
{
if (this.InvokeReq uired)
{
ReportInfoCallb ack d = new ReportInfoCallb ack(ReportInfo) ;
this.Invoke(d, msg);
}
else
{
tbResults.Appen dText(msg);
}
return msg;
}
[/code]
Now from another thread (like a timer) I can call the ReportInfo("Som e text"); function and it will handle the cross threading.

You can change up the function and the delegate to match your needs for hiding.


I see that you are also calling this.Close(), once that happens your timer dissapears too