C#程序设计（6－4）

using System;
namespace MyException
{
public class DataIsExistException: Exception
{
public DataIsExistException()
{
}
public DataIsExistException(string message)
: base(message)
{
}
public DataIsExistException(string message, Exception inner)
: base(message, inner)
{
}
}

public class App
{
public static void Main()
{
try
{
//Add(1);
Add(2);
}
catch(DataIsExistException e)
{
Console.WriteLine(e.Message);
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
}
}

public static void Add(int i)
{
if (i==1)
{
throw new DataIsExistException("HaHa");
}
else
{
throw new DataIsExistException("unKonw Exception",new DivideByZeroException());