求问如何捕获async方法中抛出的异常？

[GoingNaive]

        private async void button1_Click(object sender, EventArgs e)
        {
            try
            {
                await DoSomethingAsync();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private async Task DoSomethingAsync()
        {
            await Task.Run(() =>
            {
                Thread.Sleep(3000);
                throw new Exception("Test");
            });
        }

以上代码写法并不能catch到DoSomethingAsync抛出的异常，求问正确写法，谢谢~

[娃都会打酱油了]

Task<int> t=null;
            if (t.Exception != null)
            {
                throw t.Exception;
            }