public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private async void button1_Click(object sender, EventArgs e)
        {
            await Run();
        }
        private async Task Run()
        {
            await Task.Delay(5000); // wait for the task to finish.
            label1.Text = "test";
        }

    }