try catch 全局跳出

1.最经常的用的方式

 public static void fn()
        {
            try
            {
                int[] a = new int[4];
                a[4] = 9;
            }
            catch
            {
                throw new Exception();
            }
        }

 2.牛逼的用法

 public static void fn2()
        {
            try
            {
                fn();
            }
            catch (Exception e)
            {
                throw new Exception("", e);
            }
        }