C#

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

    Form2 form2 = new Form2();

    private void Form1_Load(object sender, EventArgs e)
    {
        // form2 gets a reference to this instance of Form1
        form2.referenceToForm1 = this;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        form2.Text = textBox1.Text;
        form2.Show();
        Hide();
    }
}

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

    // holds the reference to Form1
    public Form1 referenceToForm1 { get; set; }

    private void button1_Click(object sender, EventArgs e)
    {
        referenceToForm1.Text = textBox1.Text;
        referenceToForm1.Show();
        Hide();
    }
}

var form1 = new Form1();
var form2 = new Form2();
form1.TargetForm = form2;
form2.TargetForm = form1;

private void button1_Click(object sender, EventArgs e)
{
    this.TargetForm.Show();
    this.TargetForm.Text = textBoxform1.Text;
    Hide();
}

foreach (Task task in serverTaskList)
{
   ...
}

turbosupramk3 wrote:

How did you know it only implemented IEnumerable and not IEnumerable<T>?

devvvy wrote:

and second?