C# 5.0 async void vs async Task

 private void button1_Click(object sender, EventArgs e)
        {
            TestReturnsVoid();//会在UI Thread抛出异常，导致程序崩溃
        }

        private void button2_Click(object sender, EventArgs e)
        {
            TestReturnsTask();//会在另外一个线程抛出异常，类似TheadPool的效果
        }

        private async void TestReturnsVoid()
        {
            await Test();
        }

        private async Task TestReturnsTask()
        {
            await Test();
        }

        private async Task Test()
        {
            throw new NotImplementedException();
        }

结论
1. async void 仅仅推荐用在UI event handler
2.总是处理事件 ： TaskScheduler.UnobservedTaskException