Application remain open when using Owner.Show() for main Form

Question

I got two forms, main and second form. Since I want to navigate between them easily, while avoiding creating multiple instances of each, I used this at main form:

Form2 secondForm = new Form2();
private void btnForm2_Click(object sender, EventArgs e)
{
 secondForm.Show(this);
 Hide();
}

and the code below at second form:

private void Form2_FormClosing(object sender, FormClosingEventArgs e)
{ 
 e.cancel = true;
 Owner.Show();
 Hide();
}

Everything works just perfect, except the fact that I can't close the application. When I go to second form and back to main, close button won't work anything at all.

How can I close the program while I still use this code?

I also tried this code to see if close button is working itself:

 private void Form1_FormClosing(object sender, FormClosingEventArgs e)
 {
      MessageBox.Show("Closing");
 } 

MessageBox was shown, but nothing happened after.

Answer 1

This happen because the second Form is not closed - you use e.cancel = true on it. Add the folowing line if you want to force closure of all application windows

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
 {
     System.Windows.Forms.Application.Exit();
 } 

then in form2, you can check if close is directed from user or from Application:

void Form2_FormClosing(object sender, FormClosingEventArgs e)
{
 //close button click by user on form 2
    if(e.CloseReason == CloseReason.UserClosing)
        e.cancel = true //cancel event
   else
     e.cancel = false //close this form
}

Or you can use CloseReason.UserClosing to direct your cancellation depending on parentship. For example:

 void Form2_FormClosing(object sender, FormClosingEventArgs e)
    {

//check if closing signal is from parent
       if   (e.CloseReason == CloseReason.UserClosing.FormOwnerClosing)
         e.cancel = false //close this form
      else 
          e.cancel = true 
    }