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Csharp+Asp.net系列教程(六)
作者:武汉SEO闵涛  文章来源:敏韬网  点击数1738  更新时间:2009/4/23 10:47:05  文章录入:mintao  责任编辑:mintao
sp;     throw;//再次引发
                    }
                }
                public static void Main()
                {
                    try
                    {
                        mf2();//调用mf2()方法
                    }
                    catch(ArgumentNullException ex)
                    {
                        Console.WriteLine("Main()方法中的异常{0}",e.Message);
                    }
                }
            }//mf2()方法中的异常:值不能为空。
//Main()方法中的异常值不能为空。
        try-finally结构:即try子句后跟一个finally子句。不管try子句是如何退出的(无论正常退出,还是引发异常,甚至执行goto|break|continue|return语句退出),程序的控制权总是会被转移到finally子句执行。
    eg:
        using System;
        public class MikeCat
        {
            public static void Main()
            {
                try
                {
                    Console.WriteLine("执行try子句");
                    //goto leave;//跳转到leave标签
                    return;
                }
                finally
                {
                    Console.WriteLine("执行finally子句");
                }
                leave:
                    Console.WriteLine("执行leave标签!");
            }
        }//执行try子句执行finally子句
            try-catch-finally:即try子句后跟一个或多个catch子句及一个finally子句
        eg:
                using System;
                class MikeCat
                {
                    static void mf(string s)
                    {
                        if(s==null)
                            throw(new ArgumentNullException());//引发异常
                    }
                public static void Main()
                {
                    try
                    {
                        string s=null;
                        mf(s);//调用mf()方法,由于s=null,因此会引发异常
                    }
                    catch(ArgumentNullException ex)
                    {
                        Console.WriteLine("异常发生:{0}",ex.Message);
                    }
                    finally
                    {
                        Console.WriteLine("执行finally子句");
                    }
                }
                }

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