Only one instance allow in winforms c#

Question

Hello Members,

In my windows forms application that have menu strip. I need to make program that only allow one instance. Means from menu if user open Student and need to open another windows systems not allow him. Please help.

Answer 1

You need a program that allow only one instance of what exactly? only one instance of application? or a form?

Answer 2

Dear, Let me explain my scenario, I have a form form1 and form2.

In form1 there is Menustrip and option to open Form2. Once Form2 is open, user not allowed to do anything on form1 without closing form2.

Answer 3

I get the solution, I need to use ShowDialog() instead of Show();

Like

SybForm f = new SubForm();
f.ShowDialog(this);

Where this is instance of main form.