C# try catch嵌套

try catch嵌套以後出現異常執行順序：

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

            Console.ReadKey();


        }

        private static void errorMethod()
        {           
            try
            {
                Console.WriteLine("----------------------內層try------------------------------");
                int i = 0;
                int a = 100/i;
            }
            catch (Exception ex)
            {
                Console.WriteLine("----------------------內層catch" + ex.Message + "------------------------------");
            }
            finally {
                Console.WriteLine("----------------------內層finally------------------------------");
            }
        }

輸出結果：

內層catch處理了異常，因此沒有執行外層catch，把內層的catch註釋掉，再試下：

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

            Console.ReadKey();


        }

        private static void errorMethod()
        {           
            try
            {
                Console.WriteLine("----------------------內層try------------------------------");
                int i = 0;
                int a = 100/i;
            }
            //catch (Exception ex)
            //{
            //    Console.WriteLine("----------------------內層catch" + ex.Message + "------------------------------");
            //}
            finally {
                Console.WriteLine("----------------------內層finally------------------------------");
            }
        }

輸出結果：

總結：try catch嵌套，內層不能捕獲時，會考慮外層內否捕獲，內層能捕獲，則外層catch不執行。