2：C#TPL探秘

private async void button1_Click(object sender, EventArgs e)
        {
            #region 方法一：
            //string i1 = await F1Async();//保证异步任务执行完
            //MessageBox.Show("i1=" + i1);
            //string i2 = await F2Async();
            //MessageBox.Show("i2=" + i2);
            #endregion

            #region 方法二：
            Task<string> task1 = F1Async();
            Task<string> task2 = F2Async();
            string i1 = await task1;//这里保证task1的任务一定执行完，并不是这里才执行异步任务。
            MessageBox.Show("i2=" + i1);
            string i2 = await task2;
            MessageBox.Show("i2=" + i2);
            #endregion
        }
        static Task<string> F1Async()
        {
            MessageBox.Show("F1 Start");
            return Task.Run(() =>
            {
                System.Threading.Thread.Sleep(1000);
                MessageBox.Show("F1 Run");
                return "F1";
            });
        }
        static Task<string> F2Async()
        {
            MessageBox.Show("F2 Start");
            return Task.Run(() =>
            {
                System.Threading.Thread.Sleep(2000);
                MessageBox.Show("F2 Run");
                return "F2";
            });

        }