From not closing when calling 2nd form after this.Close()

Question

I have a form1 that opens a form2 that opens a form3. I want to return to form1 from form3 using a button.

form1

private void form2button_Click(object sender, EventArgs e)
{
    this.Hide();
    form2 f2 = new form2();
    f2.ShowDialog();
    this.Show();
}

form2

private void form3button_Click(object sender, EventArgs e)
{
    this.Close();
    form3 f3 = new form3();
    f3.ShowDialog();
}
private void exitbutton_Click(object sender, EventArgs e)
{
    this.Close();
}

form3

private void mainmenubutton_Click(object sender, EventArgs e)
{
    this.Close();
}
private void backbutton_Click(object sender, EventArgs e)
{
    this.Close();
    form2 f2 = new form2();
    f2.ShowDialog();
}

But when in form3, after clicking the back button it shows form2 but form3 is still in the background. I have fixed this by adding this.Hide(); before this.Close();

I would like to know the logic behind why this happening.

Well, no, the form3button's Click event surely should not create a new Form2 instance and the backbutton must not create a new form object when the original one is still hidden. Consider to get rid of the Hide() hack with [this solution](https://stackoverflow.com/a/10769349/17034). A well-design GUI today ought to have only one main window, you can switch its content by swapping UserControls. — Hans Passant, Oct 09 '18 at 09:31
The lesser drastic solution is to subscribe form2's FormClosing event and call this.Show() to make the form1 visible again. — Hans Passant, Oct 09 '18 at 09:37
Another way would be to pass the instance of the form you need to return to, to the form you create. Also drop the `Hide` hack — GuidoG, Oct 09 '18 at 10:51
@HansPassant the form3button creates Form3 and the backbutton creates Form2 again as it was closed when Form3 is created (there was a typo, my bad). Thanks for the solution, I didn't want to use it because I thought it was a very drastic one. — Potato, Oct 09 '18 at 14:23

score 0 · Answer 1 · edited Oct 09 '18 at 09:46

0

Is there a way to have it appear in the same position?

form2 f1 = new form2();
f1.Location = Location; //location of any form, it also clould be f3.Location if it is exists
f1.ShowDialog();

Also is there a difference between this.Hide(); and Hide(); ?

No, there isn't.

edited Oct 09 '18 at 09:46

Potato

13
6

answered Oct 09 '18 at 08:03

koviroli

1,422
1
15
27

Thanks, this leaves only the first question unanswered. – Potato Oct 09 '18 at 09:44
" Is this a correct method of doing so? " It is subjective, I don't know what's your application for, and what should your forms do. – koviroli Oct 09 '18 at 09:50

score 0 · Answer 2 · answered Oct 09 '18 at 09:42

If I understand you right then this is what you need to in order to go back to the first form:

form1:

private void form2button_Click(object sender, EventArgs e)
{
    this.Hide();
    Account form2 = new Account();
    form2.ShowDialog();
    this.Show();
}

form2:

    private void form3button_Click(object sender, EventArgs e)
    {
        this.Hide();
        form2 f2 = new form2();
        f2.ShowDialog();
        this.Close();

    }
    private void exitbutton_Click(object sender, EventArgs e)
    {
        this.Close();
    }

form3:

private void mainmenubutton_Click(object sender, EventArgs e)
{
    this.Close();
}
private void backbutton_Click(object sender, EventArgs e)
{
    this.Close();
}

Also is there a difference between this.Hide(); and Hide(); ?

No, there's no any difference

From not closing when calling 2nd form after this.Close()

2 Answers2