Calling Task and report progress from there with IProgress

Question

From my Async function i am using IProgress interface to write status into textbox but not getting expected output. where i made the mistake in my code ? i am using winform project.

public async Task<int> Getdata(int i)
        {
            IProgress<string> progress = new Progress<string>(str =>
            {
                textBox1.Text = str;
            });

            await Task.Delay(90000);
            progress.Report("Task completed "+i.ToString());
            //return Task.FromResult(10);
            return 10;
        }

        private async void btnTask1_Click(object sender, EventArgs e)
        {
            List<Task<int>> tasks = new List<Task<int>>();

            for (int i = 0; i < 5; i++)
            {
                tasks.Add(Getdata(i + 1));
            }

            var result = await Task.WhenAll(tasks);
        }

Answer 1

See this code and it is working fine.

public async Task<int> Getdata(int i)
        {
            IProgress<string> progress = new Progress<string>(str =>
            {
                textBox1.Text = str;
            });

            await Task.Delay(90000);
            progress.Report("Task completed "+i.ToString());
            return 10;
        }

        private async void btnTask1_Click(object sender, EventArgs e)
        {
            List<Task<int>> tasks = new List<Task<int>>();

            for (int i = 0; i < 5; i++)
            {
                tasks.Add(Getdata(i + 1));
            }

            var result = await Task.WhenAll(tasks);
        }

        private async void btnTask2_Click(object sender, EventArgs e)
        {
            var tasks = new List<Task<int>>();
            for (int ctr = 1; ctr <= 10; ctr++)
            {
                int baseValue = ctr;
                tasks.Add(Task.Factory.StartNew(b => (int)b * (int)b, baseValue));
            }

            var results = await Task.WhenAll(tasks);

            int sum = 0;
            for (int ctr = 0; ctr <= results.Length - 1; ctr++)
            {
                var result = results[ctr];
                textBox1.Text += result.ToString() + ((ctr == results.Length - 1) ? "=" : "+");
                sum += result;
            }
            textBox1.Text += sum.ToString();
        }