C# 抛出异常三层架构抛出

Dal层：

namespace Dal
{
public class DalClass
{
public static void errorMessage()
{
try
{
//Console.WriteLine("-----------内层try-----------");
int i = 0;
int a = 100 / i;
//Console.WriteLine("你好");

}
catch (Exception ex)
{
//Console.WriteLine("---------内层catch" + ex.Message + "-----------");
throw ex;
}
finally
{
// Console.WriteLine("---------内部finily----------");
}

}
}
}

BLL层

namespace BLL
{
public class BLLClass
{
public static void errorMessage()
{
try
{
//Console.WriteLine("-----------内层try-----------");
DalClass.errorMessage();
//Console.WriteLine("你好");

}
catch (Exception ex)
{
//Console.WriteLine("---------内层catch" + ex.Message + "-----------");
throw ex;
}
finally
{
// Console.WriteLine("---------内部finily----------");
}

}
}
}

UI层：

try
{
BLLClass.errorMessage();
//Console.WriteLine("------------外层try---------------");

}
catch (SmException ex)
{
//Console.WriteLine("------------外层catch" + ex.ToString() + "------------");

}
catch (Exception ex)
{
//Console.WriteLine("------------外层catch" + ex.Message + "------------");

}
finally
{
// Console.WriteLine("---------外层finally--------------");
}