各Formで別Formを表示するときのコード

        private void button1_Click(object sender, EventArgs e)
        {
            var form = new Form2();
            this.Hide();
 
        if (form.ShowDialog() == DialogResult.Cancel)
        {
            this.Show();
        }
    }
 
    private void button2_Click(object sender, EventArgs e)
    {
 
        var form = new Form3();
        this.Hide();
 
        if (form.ShowDialog() == DialogResult.Cancel)
        {
            this.Show();
        }
    }