Passing data between two forms with properties [duplicate]

In form2 you need to create event and subscribe to it in form1. Thats all.

//declare event in form 2
public event EventHandler SomeTextInSomeFormChanged;

// call event in form2 text_changed event
if(SomeTextInSomeFormChanged != null)
   SomeTextInSomeFormChanged(this, null);

//in form 1 subcribe to event
var form2 = new Form2();
form2.SomeTextInSomeFormChanged += SomeHandlerInForm1WhereYouCanSetForcusInForm1

Update:

Form2:

public Form2()
{
    InitializeComponent();
}

public void button1_Click(object sender, EventArgs e)
{
//if subscribers exists
  if(SomeTextInSomeFormChanged != null)
  {
    SomeTextInSomeFormChanged(form2_textBox1, null);
  }
}

Form1:

public partial class Form1 : Form { 

   public Form1() { InitializeComponent(); }

    private void form1_button1_Click(object sender, EventArgs e)
    {
        Form2 f2 = new Form2();
        f2.Show();
        f2.SomeTextInSomeFormChanged +=new EventHandler(f2_SomeTextInSomeFormChanged);  
    }

    public void f2_SomeTextInSomeFormChanged(object sender, EventArgs e)
    {
        var textBoxFromForm2 = (TextBox)sender;
        form1_textBox1.Text =  textBoxFromForm2.Text
        this.Focus();
    }
}

The website listed below has very good tutorials. This particular page demonstrates how this can be achieved:

http://www.vcskicks.com/data-between-forms.php