原来···是不是高手，看try cathch都能看出来···

先看一段代码：

    internal class ThrowAndThrowEx
    {
        public static void Test ()
        {
            Class1.DoSomething();
        }
    }


    public class Class1
    {
        public static void DoSomething ()
        {
            try
            {
                Class2.DoSomething();
            }
            catch (Exception ex)
            {
                //throw;
                throw new Exception("class1 call class2", ex);

            }
        }
    }


    public class Class2
    {
        public static void DoSomething ()
        {
            try
            {
                Class3.DoThrowOrThrowEx();
            }
            catch (Exception ex)
            {
                throw;
                //throw ex;
            }
        }


    }


    public class Class3
    {
        public static void DoThrowOrThrowEx ()
        {
            try
            {
                int divider = 0;
                int number = 5 / divider;
            }
            catch (Exception ex)
            {
                throw ex;
                //throw;
            }
        }

    }

如此来看 

可以在一些关键的分层次的地方使用:

                throw new Exception("class1 call class2", ex);

其他地方使用:

                throw;