C# winforms How to Prevent form from opening multiple times

This tutorial is about how to check if a form is already open c# and to prevent form from opening or showing same form multiple times.

[carilevel]

THANKS DUDE, THIS IS HELP ME A LOT!, u will get new subs

[haqkiemdaim]

WORKS LIKE A CHARM !!! Thank you so much!

[milosbanda]

f.Text doesn't work for me, but f.Name works.

[conform]

Thanks a Lot, but if from are minimize or user trying to recall with click from btn then how to maximize this FRM

Thank you... you have make this very easy & True.
But after this code How to pass value from one form to another.?

[louisrumunu]

Thanks a lot, I was really hustling for this

[jennaho]

Doesn't work for me. the form keeps opening(duplicating everytime I click the button)

[gladdenitiowe]

What do you do when you're not able to use the Isopen variable

[prasadmaharnur]

How to overcome same problem in Microsoft visual studio 2019 wpf

[aryanbhaskar]

In your case Click button is not opening the form again !! I m stuck on here i hv matched ur codes.

[sherzafariqbal]

Bhai boht sare forms k liye aik hi code kese kam karega? Please help us.

[raghvirsingh]

sir how to prevent tabpage to reopen in c# visual studio, as i have my tabpages in tabcontrol when i click a button to open it, it open but if again click the button it reopens again

[digitalmanojjoshi]

When we close form 2 and click again on button error comes

[davidg]

English title and description, but the video is in another language....

[KamrulHasan-tvso]

bool Isopen = false;
foreach(Form f in Application.OpenForms)
{
if(f.Name == "AddCustomer")
{
Isopen = true;
f.WindowState = FormWindowState.Maximized;
f.BringToFront();
break;
}
}
if(Isopen == false)
{
AddCustomer addcus = new AddCustomer();
addcus.Show();
}

[pawka]

bad code, just change Form.Show() to .ShowDialog()