Open Form2 from Form1, close Form1 from Form2

Question

Now, I have two forms, called form1 and form2, in the form1 there's a button, when I click it, then open the form2

Question: in the form2, I want to create a button when I click it, the form2 close and the form1 close. How to do?this

Answer 1

Form1:

    private void button1_Click(object sender, EventArgs e)
    {
        Form2 frm = new Form2(this);
        frm.Show();
    }

Form2:

public partial class Form2 : Form
{
    Form opener;

    public Form2(Form parentForm)
    {
        InitializeComponent();
        opener = parentForm;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        opener.Close();
        this.Close();
    }
}