Refresh Form on Visual Studio 2013 [C#]

Question

How can I refresh an open form from another form?

For example:

Form 1

Label (Modifiers = Public)

Button (To show Form 2)

Form 2

Text Box (Enter value for Label and display it on label)
Button (Sends value to Label)

I've notice that after I entered value in text box, the label is not updating after I closed form 2.

Answer 1

what if I use this method? Is there any disadvantage? or it's fine?

Form 1: Modifiers of label1 is Public

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

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

Form 2:

public partial class Form2 : Form
{
    public Form2()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        (this.Owner as Form1).label1.Text = textBox1.Text;
    }
}

Answer 2

For C# Winforms, this is how I'd do it.

Form 1:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        Form2 oForm = new Form2();
        oForm.ChangeLabelText += ChangeLabelText;
        oForm.Show();
    }

    private void ChangeLabelText(object sender, EventArgs e)
    {
        string sText = sender as string;
        label1.Text = sText;
    }

Form 2:

public partial class Form2 : Form
{
    public event EventHandler ChangeLabelText;
    public Form2()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        string sText = textBox1.Text;
        ChangeLabelText(sText, null);
    }
}