实现多个catch块

要了解try...catch...finally块是如何工作的，最简单的方式是用示例来说明。示例SimpleException.它多次要求用户输入数字，然后显示这个数字。为了便于解释这个示例，假如必须在0~5之间。否则程序就不能对该数字进行正确的处理。所以，如果用户输入超出该范围的数字，就会抛出异常。
Using System；
namespace Wrox.ProCSharp.AdvancedCSharp
{
public class MainEntryPoint
{
   while (true)
            {
                try
                {
                    string userInput;
                    Console.WriteLine("input a number between 0 and 5" + "(or just hit return to exit)>0");
                    userInput = Console.ReadLine();
                    if (userInput == "")
                    {
                        break;
                    }
                    int index = Convert.ToInt32(userInput);
                    if (index < 0 || index > 5)
                    {
                        throw new IndexOutOfRangeException("you typed in" + userInput);
                    }
                    Console.WriteLine("your number was" + index);
                }
                catch (IndexOutOfRangeException ex)
                {
                    Console.WriteLine("Exception:" + "Number should be between 0 and 5.{0}", ex.Message);
                }
                catch(Exception ex)
                {
                    Console.WriteLine("An exception was thrown.Message was:{0}",ex.Message);
                }
                finally
                {
                    Console.WriteLine("Thank you");
                }
            }
}
}