static void Main(string[] args)
        {
            int input = 0;
            do
            {
                Console.WriteLine("请选择题目：");
                Console.WriteLine("1-字符串包含,3-退出\r\n");
                string inputtemp = Console.ReadLine();
                try
                {
                    input = Int32.Parse(inputtemp);
                }
                catch
                {
                    Console.WriteLine("请选择题目：");
                    Console.WriteLine("1-字符串包含，3-退出\r\n");
                    inputtemp = Console.ReadLine();
                }
                switch (input)
                {
                    case 1:
                        IsContain(); input = 0;
                        break;
                 }
            } while (input != 3);
        }
 
 private static void IsContain()
        {
            int count = 0;//匹配的个数
            int tempi = 0;//在字符1 中开始匹配的位置
            string str1, str2;//字符串1 字符串2
            bool result = false;//是否包含 默认 不包含
            Console.WriteLine("Please enter 1st string Word：");
            str1 = Console.ReadLine();
            Console.WriteLine("Please enter 2ed string Word：");
            str2 = Console.ReadLine();
            //VS2008 系统自带 方法1
            //if (str1.Contains(str2))
            //{
            //    result = true;
            //}
            //VS2008 系统自带 方法2
            //if (str1.IndexOf(str2) > -1)
            //{
            //    result = true;
            //}
            //VS2008 系统自带 方法3
            //string[] strs = { str2 };
            //if (str1.Split(strs, StringSplitOptions.None) > 1)
            //{
            //    result = true;
            //}

            //以下自己写的
            //如果输入相等 则一定包含
            if (str1 == str2)
            {
                result = true;
            }
            //只有 str1长度 大于等于 str2时 才有包含可能
            if (str1.Length >= str2.Length)
            {
                char[] cstr1 = str1.ToCharArray();//转为字符处理
                char[] cstr2 = str2.ToCharArray();
                for (int i = 0; i < cstr1.Length; i++)//遍历str1
                {
                    if (cstr1.Length - i >= cstr2.Length)
                    {//当 str1剩余的字符数 多于str2时 才有可能，否则不可能而跳出循环
                        count = cstr2.Length;//匹配的个数
                        tempi = i;//在字符1 中开始匹配的位置
                        for (int j = 0; j < cstr2.Length; j++)
                        {
                            //从字符1匹配处 开始比较 str2中的全部字符
                            if (cstr1[tempi] == cstr2[j])
                            {
                                count--;
                                tempi++;
                            }
                            else
                            {
                                break;
                            }
                        }
                        if (count == 0)
                        {//说明 全部匹配
                            result = true;
                            count = cstr2.Length;//修正 匹配的个数
                            tempi = i;//修正 在字符1 中开始匹配的位置
                            break;
                        }
                    }
                    else
                    {
                        break;
                    }
                }              
            }
            if (result)//如果包含
            {
                string str = str1.Substring(0, tempi);
                str += "(";//用括号 扩住包含的内容，当然只有第一个
                str += str1.Substring(tempi, count);
                str += ")";
                if (tempi + count != str1.Length)
                {
                    str += str1.Substring(count + tempi);
                }
                Console.WriteLine("输入的第一个字符串包含第二个字符串：{0}", str);
            }
            else
            {
                Console.WriteLine("输入的第一个字符串：{0}不包含第二个字符串：{1}", str1, str2);
            }
        }