Record how to modify the control across threads

Talk is cheap, Show you the code first！

        private async  void Form1_Load(object sender, EventArgs e)
        {
    
            var t = Task.Run(() =>
            {
    
                Thread.Sleep(TimeSpan.FromSeconds(2));
                return "hello";
            });
            lb.Text = await t;
            timer1.Enabled = true;
            timer1.Interval = 2000;
        }

        private async void timer1_Tick(object sender, EventArgs e)
        {
    

            var t = Task.Run(() =>
            {
    
                Thread.Sleep(TimeSpan.FromSeconds(5));
                
                return string.Format("{0:U}", DateTime.Now);
            });
            lb.Text = await t;
        }

Hint await Its function is to split ,await Before and after, it will be processed in two threads .

For specific articles, please refer to
C# Understand thoroughly async/await - Five dimensional thinking - Blog Garden
https://www.cnblogs.com/zhaoshujie/p/11192036.html