How to check if form is open, if open close form?

Question

How do I check if a form is open, and if it is open to close the form?

I tried the following, testing out some code but it keep saying the form is not open even when I know it is:

 foreach(Form a in Application.OpenForms) 
 {
     if (a is YouLikeHits_Settings) 
     {
         // About form is open
         MessageBox.Show("form open");
         break;
     }
     // About form is not open...
     MessageBox.Show("form not open");
     break;
 }

score 20 · Accepted Answer · answered Nov 18 '12 at 22:13

20

Application.OpenForms contains opened forms. If form in this collection, then it is opened. Otherwise it is not opened (possibly closed).

if (Application.OpenForms.OfType<YouLikeHits_Settings>().Any())
    MessageBox.Show("Form is opened");
else
    MessageBox.Show("Form is not opened");

answered Nov 18 '12 at 22:13

Sergey Berezovskiy

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Was I did was make a button which opens the form, then in another button I put in the code above, when I click it, it keeps saying, form is not open. – Edwin Torres Nov 18 '12 at 22:14
1

Your code worked to detect it being open :). Any way after it pops up with the message box that the form is open I can close that certain form? – Edwin Torres Nov 18 '12 at 22:16
1

Yes, you can: `Application.OpenForms.OfType().First().Close()` – Sergey Berezovskiy Nov 18 '12 at 22:18
i have tried it but my certainly form open cannot be closed automaticly – aminvincent Feb 17 '16 at 10:54
@SergeyBerezovskiy i have same problem like this.. i tried your suggest code and it ran well when i show my form using `form1.show();` but when i tried use `form1.showdialog();` the form cannot be closed. if any suggest for me i will say thanks so much – aminvincent Feb 18 '16 at 01:29
@aminvincent I think you should create new question with all related to your problem information and code to reproduce issue. – Sergey Berezovskiy Feb 18 '16 at 07:26
@SergeyBerezovskiy thanks for your suggest,..finally i create new question and this the link that i created and that it solved: http://stackoverflow.com/questions/35471376/close-messagebox-when-incoming-new-message/35471810?noredirect=1#comment58640277_35471810 – aminvincent Feb 19 '16 at 08:07
Many thanks, it worked like a charm and exactly what you said and I needed :) – Juano Jun 26 '20 at 06:05

score 1 · Answer 2 · answered Jun 30 '16 at 06:00

This will work sure

            if (Application.OpenForms.OfType<frm_YouLikeHits_Settings>().Any())
            {
                Application.OpenForms.OfType<frm_YouLikeHits_Settings>().First().Close();
            }
            frm_YouLikeHits_Settings f1= new frm_YouLikeHits_Settings();
            f1.MdiParent = this;
            f1.Show();

score 0 · Answer 3 · edited May 26 '18 at 01:35

0

try
{
    if (Application.OpenForms.OfType<talkForm>().Any())
    {
        talkForm frm = new talkForm();
        frm.Close();
        MessageBox.Show("Form is opened");
    }
    else
    {
        talkForm frm = new talkForm();
        frm.Show();
        MessageBox.Show("Form is not opened");
    }
}
catch(Exception ex)
{

}

edited May 26 '18 at 01:35

Stephen Rauch

47,830
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answered May 26 '18 at 01:15

John G

319
4
8

How to check if form is open, if open close form?

3 Answers3

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