C# try catch嵌套

try catch嵌套之后出现异常执行顺序：

static void Main(string[] args)
        {
            try
            {
                Console.WriteLine("----------------------外层try------------------------------");
                errorMethod();
            }
            catch (Exception ex)
            {
                Console.WriteLine("----------------------外层catch" + ex.Message + "------------------------------");
            }
            finally {
                Console.WriteLine("----------------------外层finally------------------------------");
            }

            Console.ReadKey();

        }

        private static void errorMethod()
        {
            try
            {
                Console.WriteLine("----------------------内层try------------------------------");
                int i = ;
                int a = /i;
            }
            catch (Exception ex)
            {
                Console.WriteLine("----------------------内层catch" + ex.Message + "------------------------------");
            }
            finally {
                Console.WriteLine("----------------------内层finally------------------------------");
            }
        }

输出结果：

内层catch处理了异常，所以没有执行外层catch，把内层的catch注释掉，再试下：

static void Main(string[] args)
        {
            try
            {
                Console.WriteLine("----------------------外层try------------------------------");
                errorMethod();
            }
            catch (Exception ex)
            {
                Console.WriteLine("----------------------外层catch" + ex.Message + "------------------------------");
            }
            finally {
                Console.WriteLine("----------------------外层finally------------------------------");
            }

            Console.ReadKey();

        }

        private static void errorMethod()
        {
            try
            {
                Console.WriteLine("----------------------内层try------------------------------");
                int i = ;
                int a = /i;
            }
            //catch (Exception ex)
            //{
            //    Console.WriteLine("----------------------内层catch" + ex.Message + "------------------------------");
            //}
            finally {
                Console.WriteLine("----------------------内层finally------------------------------");
            }
        }

输出结果：

总结：try catch嵌套，内层不能捕获时，会考虑外层内否捕获，内层能捕获，则外层catch不执行。