Loop through all MDI children and close all other forms except the current

Question

I am working on a winforms application using c#. I have an MDI container that has a menu on the left and by pushing a button then the appropriate form is visible. If I click for ex 3 times the button which opens Form1 the 6 instances of the form are opened. Thus I thought that I have to write a method that disposes any other Form1 instances. With the following method, I'm looping through the MDI children, but I want some help how to close all other instances except the new one.

  public void DisposeAllButThis(Form form)
    {
        foreach (Form frm in this.MdiChildren)
        {
            if (frm == form)
            {
                frm.Dispose();
                return;
            }
        }
    }

score 9 · Accepted Answer · edited May 23 '17 at 11:46

9

You need to check whether the form is of the same type too:

public void DisposeAllButThis(Form form)
{
    foreach (Form frm in this.MdiChildren)
    {
        if (frm.GetType() == form.GetType() 
            && frm != form)
        {
            frm.Dispose();
            frm.Close();
        }
    }
}

For more information on Close and Dispose see: C# Form.Close vs Form.Dispose

edited May 23 '17 at 11:46

Community

1
1

answered Jul 03 '12 at 10:22

Emond

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BTW: I just changed the code a bit by removing the premature return statement in the loop! – Emond Jul 03 '12 at 11:54
you are not disposing the form before closing it. – Pankaj Feb 02 '17 at 00:25
@Helper - I added the call to Dispose. BTW: if these forms are visible calling Close is sufficient – Emond Feb 02 '17 at 06:31
you should dispose first and then make it closed. – Pankaj Feb 02 '17 at 07:30

score 2 · Answer 2 · edited Feb 02 '17 at 00:24

2

public void DisposeAllButThis(Form form)
{
    foreach (Form frm in this.MdiChildren)
    {
        if (frm != form)
        {
            frm.Dispose();   
            frm.Close();          
        }
    }
    return;
}

edited Feb 02 '17 at 00:24

Pankaj

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answered Jul 03 '12 at 10:43

Andriy Vandych

21
1

score 1 · Answer 3 · answered Jul 03 '12 at 10:20

1

foreach (Form frm in this.MdiChildren)
{
   if (frm != form)
   {
      frm.Dispose();
      return;
   }
}

answered Jul 03 '12 at 10:20

Asif Mushtaq

13,010
3
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score 0 · Answer 4 · answered Aug 21 '13 at 19:31

By this fanction You can call it from another class : and note of this : frm.GetType() != Parent.GetType()

public void DisposeAllButThis(Form parentForm)
    {
        foreach (Form frm in Parent.MdiChildren)
        {
            if (frm.GetType() != Parent.GetType()
                && frm != Parent)
            {
                frm.Close();
            }
        }
    }

score 0 · Answer 5 · answered Feb 11 '16 at 15:22

0

private void closallforms()
        {
            foreach (Form frm in this.MdiChildren)
            {
                if (frm != Parent)
                {
                    frm.Close();
                }
            }
        }

answered Feb 11 '16 at 15:22

Dara.Joukar

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2

The answer can become more valuable if you added some explanation and links to documentation, so the original poster and other users can actually learn from it. – Markus Safar Feb 11 '16 at 16:42

score 0 · Answer 6 · answered Jun 19 '19 at 16:40

if you call from another child form you can use: this.DisposeAllButThis(this.FindForm());

and use the method:

private void DisposeAllButThis(Form form)
{
    foreach (Form frm in ParentForm.MdiChildren)
    {
       if (frm != form)
       {
          frm.Dispose();
          frm.Close();
       }
    }
 }

score 0 · Answer 7 · edited Jun 07 '22 at 23:46

0

if (ActiveMdiChild != null)
    ActiveMdiChild.Close();

edited Jun 07 '22 at 23:46

Samuel Diogo

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answered Jun 07 '22 at 13:49

Hasher Hanif

1

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Hi, you need give more information inv your anwser – Samuel Diogo Jun 07 '22 at 17:01

Loop through all MDI children and close all other forms except the current

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