استفاده از متد یک فرم در فرم دیگر

// Code from Form 1
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    private void button1_Click(object sender, EventArgs e)
    {
        Form2 objForm2 = new Form2();
        objForm2.PassValue += new PassValueHandler(objForm2_PassValue);
        objForm2.Show();
    }
    public void objForm2_PassValue(string strValue)
    {
        label1.Text = strValue;
    }
}

// Code From Form 2
public delegate void PassValueHandler(string strValue);
public partial class Form2 : Form
{
    public event PassValueHandler PassValue;

    public Form2()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        if (PassValue != null)
        {
            PassValue(textBox1.Text);
        }
        this.Close();
    }
}