程序员的博客: C Sharp基础

1. C#基础

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            Console.WriteLine("hello !");
            string s=Console.ReadLine();//用户输入文字时，程序是暂停的，回车后把输入的作为返值，并存放到s当中
            Console.WriteLine(s+"你好");//输出用户输入的

            int i1 = 10;
            int i2 = 20;
            //Console.WriteLine(i1+"+"+i2+"="+(i1+i2));//方法一
            Console.WriteLine("{0}+{1}={2}",i1,i2,i1+i2,"aaa");//方法二
            //使用占位符，{0}{1}{2}分别表示三个占位符,顺序从0开始

            Console.WriteLine("请输入男孩的名字");
            string boy = Console.ReadLine();
            Console.WriteLine("请输入女孩的名字");
            string girl = Console.ReadLine();
            Console.WriteLine("{0}爱{1}",boy,girl);
            */
            /*
            string s1 = "\"ab\"";
            Console.WriteLine(s1);
            string s2 = "a\nb";
            Console.WriteLine(s2);
            string s3 = @"c:\temp\user\new\1.jpg";//@表示字符串中的\不当成转义符,@只针对转义符
            Console.WriteLine(s3);
            */

            Console.WriteLine("请输入第一个数字");
            string s4 = Console.ReadLine();
            int i1 = Convert.ToInt32(s4);

            Console.WriteLine("请输入第二个数字");
            //string s5 = Console.ReadLine();
            //int i2 = Convert.ToInt32(s5);
            int i2 = Convert.ToInt32(Console.ReadLine());

            Console.WriteLine("{0}+{1}={2}",i1,i2,i1+i2);

            //中文做变量名
            string 姓名 = Console.ReadLine();
            Console.WriteLine(姓名+" 你好");

            人人1 = new 人();
            人1.年龄 = 20;
            人1.说话();

            Console.ReadKey();//按下一个按键继续执行
        }
    }
}
///////////////////////////////////////////////////////////////

//人.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class 人
    {
        public int 年龄 { get; set; }
        public void 说话()
        {
            Console.WriteLine(年龄+" 说话");
        }
    }
}

2. 字符串

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Cast入门
{
    class Program
    {
        static void Main(string[] args)
        {
            //类型转换
            Console.WriteLine("int最大值{0}，最小值{1}",int.MaxValue,int.MinValue);
            Console.WriteLine("byte最大值{0}，最小值{1}",byte.MaxValue,byte.MinValue);
            byte b = 3;
            int i1 = b;
            //b = i1;
            b = (byte)i1;

            string s = "123";
            int i2 = Convert.ToInt32(s);
            Console.WriteLine(i2);

            Console.ReadKey();
        }
    }
}
////////////////////////////////////////////////

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 字符串
{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            char c1='a';
            char c2='b';
            string s1 = "hi";
            string s2 = "a";
            string s3 = "";

            string s4 = "hello";
            Console.WriteLine(s4.Length);//5, 不是6,和C语言不同不考虑'\0'
            Console.WriteLine(s4[1]);
            char c3=s4[3];

            for (int i = 0; i < s4.Length; i++)
            {
                char c6=s4[i];
                Console.WriteLine(c6);
            }

            for (int i = s4.Length - 1; i >= 0; i--)
            {
                Console.WriteLine(s4[i]);
            }
            //s4[0]='y';//不能赋值
            */

            /*
            string s1 = "hello";
            char[] chars = s1.ToCharArray();//将字符串转换成字符数组
            chars[0]='a';
            string s2 = new string(chars);
            Console.WriteLine(s1);
            Console.WriteLine(s2);
            */

            string s1 = "hello";
            string s10=s1;
            char[] chars = s1.ToCharArray();
            chars[0]='a';
            s1 = new string(chars);
            Console.WriteLine(s1);
            Console.WriteLine(s10);

            Console.ReadKey();
        }
    }
}

3. 枚举学习

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 枚举学习
{
    enum Gender { Male,Female,Unknown};//声明枚举
    class Program
    {
        static void Main(string[] args)
        {
            Gender g = Gender.Female;//枚举的意义在于限定变量的取值范围
            //Gender g1 = Gender.Male;
            /*
            string s = "Male";
            if (s == "Male")
            {
                Console.WriteLine("女");
            }
            else if (s == "Unknown")
            {
                Console.WriteLine("未知");
            }
            esle
            {
                Console.WriteLine("非法输入！");
            }
            */
        }
    }
}

4. 条件判断

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 条件判断
{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            string s1 = Console.ReadLine();
            int age = Convert.ToInt32(s1);
            if (age > 20)
            {
                Console.WriteLine("成年人");
            }
            //else
            //{
            //    Console.WriteLine("小屁孩");
            //}

            else if (age > 10)
            {
                Console.WriteLine("儿童");
            }
            else
            {
                Console.WriteLine("婴幼儿");
            }
            */

            /*
            Console.WriteLine("请输入密码");
            string s1 = Console.ReadLine();
            if (s1 == "888888")
            {
                Console.WriteLine("密码正确");
            }
            else
            {
                Console.WriteLine("密码错误，请再输入一次");
                s1 = Console.ReadLine();
                if (s1 == "888888")
                {
                    Console.WriteLine("密码正确");
                }
                else
                {
                    Console.WriteLine("密码错误");
                }
            }
             */

            /*
            Console.WriteLine("请输入用户名：");
            string username = Console.ReadLine();
            Console.WriteLine("请输入密码：");
            string password = Console.ReadLine();
            if (username == "admin" && password == "888888")
            {
                Console.WriteLine("正确");
            }
            else
            {
                Console.WriteLine("用户名、密码错误");
                if (username != "admin")
                {
                    Console.WriteLine("用户名不存在");
                }
            }
            */

            Console.WriteLine("请输入年龄");
            string strAge = Console.ReadLine();
            int age = Convert.ToInt32(strAge);
            if (age > 18)
            {
                Console.WriteLine("可以查看！");
            }
            else if (age < 10)
            {
                Console.WriteLine("不允许查看！");
            }
            else
            {
                Console.WriteLine("是否继续查看(yes、no)?");
                string isContinue=Console.ReadLine();
                if (isContinue == "yes")
                {
                    Console.WriteLine("看吧！");
                }
                else if (isContinue == "no")
                {
                    Console.WriteLine("乖！");
                }
                else
                {
                    Console.WriteLine("输入错误");
                }
            }
            Console.ReadKey();
        }
    }
}

5. 数组

6. 变量命名

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 变量命名
{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            int i1;
            int i2,i3;
            int i4 = 8;
            i4++;
            Console.WriteLine(i4);
            */
            /*
            int i=10;
            i = 1 + i;
            i += 2;
            Console.WriteLine(i);

            int x = 10;
            int y ;
            y = x + 80;
            Console.WriteLine(y);
            */
            /*
            //交换两变量的值
            int i1 = 10;
            int i2 = 20;
            Console.WriteLine("i1={0},i2={1}",i1,i2);

            int i3;
            i3 = i1;
            i1 = i2;
            i2 = i3;
            Console.WriteLine("i1={0},i2={1}",i1,i2);
            */

            //布尔运算
            int i = 30;
            bool b=(i==1);
            Console.WriteLine("{0}\nb:{1}",i==1,b);
            Console.WriteLine("i:{0}",i=1);
            Console.WriteLine("{0}",i!=30);

            int i1 = 20;
            int i2 = 30;
            Console.WriteLine("{0}",i1>10&&i2<100);
            Console.WriteLine("{0}",i1>100&&i2<100);
            Console.WriteLine("{0}",i1>200||i2<100);

            Console.ReadKey();
        }
    }
}

7. 函数

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 函数
{
    class Program
    {
        static void Main(string[] args)
        {
            int i = ReadInt();
            i++;
            Console.WriteLine(i);
            Console.WriteLine(Max(30,50));

            string[] names = { "tom","jerry","lucy"};
            string s = Join(names,"|");
            Console.WriteLine(s);

            Console.ReadKey();
        }
        /*
        static int ReadInt()
        {
            string s = Console.ReadLine();
            int i = Convert.ToInt32(s);
            return;
        }
        */
        static int CT(string s)
        {
            if (s == "tom")
            {
                return 1;
            }
            if (s == "jerry")
            {
                return 0;
            }
            return -1;
        }

        static void SayHello()
        {
            int i = 3;
            if (i > 10)
            {
                return;
            }
            Console.WriteLine("哈喽哇！");
        }

        static int ReadInt()
        {
            string s = Console.ReadLine();
            return Convert.ToInt32(s);
        }

        static int Max(int i1, int i2)
        {
            if (i1 > i2)
            {
                return i1;
            }
            return i2;
        }

        static int Sum(int[] values)
        {
            int sum = 0;
            foreach (int i in values)
            {
                sum = sum + i;
            }
            return sum;
        }

        static string Join(string[] strs, string seperator)
        {
            string result = "";
            for (int i = 0; i < strs.Length - 1; i++)
            {
                result = result + strs[i] + seperator;
            }
            if (strs.Length > 0)
            {
                result = result + strs[strs.Length - 1];
            }
            return result;
        }
    }
}
///////////////////////////////////////////////

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 函数2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("{0}{1}{2}{3}{4}",333,55,66,77,88,99,10,"aaa");
            string[] values = { "aaa","bbb","ccc"};
            VFunc("aaa","111","222","33233","fasfsa","aaa");
            SayHello("tom","张大虎","狗蛋");
            Console.ReadKey();
        }

        static void VFunc(params string[] values)//加params说明这个函数参数个数可变
        {
            foreach (string s in values)
            {
                Console.WriteLine(s);
            }
        }

        static void SayHello(string name, params string[] nicknames)
        {
            Console.WriteLine("我的名字是{0}",name);
            foreach(string nickname in nicknames)
            {
                Console.WriteLine("我的昵称：{0}",nickname);
            }
        }
    }
}

8. 函数重载

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 函数重载
{
    class Program
    {
        static void Main(string[] args)
        {
            SayHello("王大壮");
            SayHello("tom");
            SayHello(20);
            //string s = SayHello("jerry");
            SayHello("tom","littletom");
            Console.ReadKey();
        }

        static void SayHello(string name)
        {
            Console.WriteLine("大家好,我是:{0}",name);
        }
        /*
        static void SayHello(string name)
        {
            Console.WriteLine("Hello,I am {0}",name);
        }
        */

        static void SayHello(int age)
        {
            Console.WriteLine("我{0}岁了",age);
        }

        /*
        static string SayHello(string name)
        {
            return "大家好,我是"+name;
        }
         */
        static void SayHello(string name, string nickname)
        {
            Console.WriteLine("我的名字是{0},我的昵称是{1}",name,nickname);
        }
    }
}

9. For例子

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace For例子
{
    class Program
    {
        static void Main(string[] args)
        {
            int i = 0;
            for (i = 10; i < 20; i++)
            {
                Console.WriteLine(i);
            }
            //Console.ReadKey();

            for ( i = 10; i > 0; i--)
            {
                Console.WriteLine(i);
            }
            Console.ReadKey();
        }
    }
}

10. While语句

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace While语句
{
    class Program
    {
        static void Main(string[] args)
        {
            //while (true)
            //{
            //    Console.WriteLine("我在运行！");
            //}

            //int i = 0;
            //while (i < 10)
            //{
            //    i++;
            //    Console.WriteLine(i);
            //}

            //int i = 1;
            //int sum = 0;
            //while (i <= 100)
            //{
            //    sum = sum + i;
            //    i++;
            //}
            //Console.WriteLine("{0}",sum);

            //Console.WriteLine("请输入用户名：");
            //string username = Console.ReadLine();
            //Console.WriteLine("请输入密码：");
            //string password = Console.ReadLine();

            //while (username != "admin" || password != "888888")
            //{
            //    Console.WriteLine("用户名、密码错误！");
            //    Console.WriteLine("请重新输入用户名");
            //    username = Console.ReadLine();
            //    Console.WriteLine("请输入密码");
            //    password = Console.ReadLine();
            //}

            //Console.WriteLine("请输入一个数字");
            //string s = Console.ReadLine();

            //while (s != "q")
            //{
            //    int number = Convert.ToInt32(s);
            //    Console.WriteLine("{0}",number*2);
            //}

            //while (true)
            //{
            //    Console.WriteLine("请输入一个数字");
            //    string s = Console.ReadLine();
            //    if (s == "q")
            //        return;
            //    int number = Convert.ToInt32(s);
            //    Console.WriteLine("{0}",number*2);
            //}

            //int max = 0;
            //while (true)
            //{
            //    Console.WriteLine("请输入一个数字(结束请输入end):");
            //    string s = Console.ReadLine();
            //    if (s == "end")
            //    {
            //        Console.ReadLine();
            //        return;
            //    }
            //    int number = Convert.ToInt32(s);
            //    if (number > max)
            //    {
            //        max = number;
            //    }
            //}

            //int i = 0;
            //while (i < 12)
            //{
            //    Console.WriteLine("i={0}",i);
            //    i++;
            //    if (i == 10)
            //    {
            //        return;
            //    }
            //    Console.WriteLine("自增以后i={0}",i);
            //}
            //Console.WriteLine("before ReadKey");

            int sum = 0;
            int i = 1;
            while (i <= 100)
            {
                if ((i % 7) == 0)
                {
                    i++;
                    Console.WriteLine(i-1);
                    continue;
                }
                sum = sum + i;
                i++;
            }
            Console.WriteLine("{0}",sum);

            Console.ReadKey();
        }
    }
}

11. Switch语句

12. refout参数

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace refout参数
{
    class Program
    {
        static void Main(string[] args)
        {
            int age = 20,age1=20;
            IncAge(age);
            IncAge2(out age);
            IncAge(ref age1);

            Console.WriteLine("无ref:\t"+age);
            Console.WriteLine("加了ref:\t"+age1);

            int i1 = 10;
            int i2 = 20;
            Console.WriteLine("交换前:\ni1:{0},i2{1}",i1,i2);
            Swap(ref i1,ref i2);
            Console.WriteLine("交换后:\ni1={0},i2={1}",i1,i2);

            Console.ReadKey();
        }

        static void IncAge(int age)//IncAge内部改变的是副本
        {
            age++;
        }


        static void IncAge(ref int age)
        {
            age++;
        }

        static void IncAge2(out int age)
        {
            age=30;
            Console.WriteLine("加了out的调用："+age);
        }

        static void Swap(ref int i1,ref int i2)
        {
            int temp=i1;
            i1=i2;
            i2=temp;
        }
    }
}

13. 字符串练习1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 字符串练习1
{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            //接收用户输入的字符串，将其反序输出
            string s = Console.ReadLine();
            for (int i = s.Length-1; i >= 0; i--)
            {
                Console.Write(s[i]);
            }
             */
            /*
            //将一句话中的单词反序输出
            string s1 = Console.ReadLine();
            string[] words = s1.Split(' ');
            for (int i = words.Length - 1; i >= 0; i--)
            {
                Console.Write(words[i]+" ");
            }
            Console.WriteLine("\n-------------");

            //从email中提取用户名与域名
            string email = Console.ReadLine();
            int atIndex = email.IndexOf('@');
            string username = email.Substring(0,atIndex);
            string 域名 = email.Substring(atIndex+1);
            Console.WriteLine(username);
            Console.WriteLine(域名);
            */
            /*
            //提出文件中的文章标题与作者
            string[] lines = System.IO.File.ReadAllLines(@"..\..\2.txt", Encoding.Default);
            foreach (string line in lines)
            {
                //string[] strs = line.Split('');
                string[] strs = line.Split(new char[]{' '},StringSplitOptions.RemoveEmptyEntries);
                string title=strs[0];//标题
                string author=strs[1];//作者
                title=title.Substring(0,Math.Min(17,title.Length));//截取标题的前17个字符
                //Math.Min用来计算两个数中的最小值
                title = title + "...";
                Console.WriteLine("{0}|{1}",title,author);
            }
             */

            string value = GetConfigValue(@"..\..\3.ini","端口");
            Console.WriteLine(value);

                Console.ReadKey();
        }

        static string GetConfigValue(string filename, string itemName)
        {
            string[] lines = System.IO.File.ReadAllLines(filename,Encoding.Default);
            foreach (string line in lines)
            {
                string[] strs = line.Split('=');
                string name=strs[0];
                string value=strs[1];
                if (name.Trim() == itemName)
                {
                    return value.Trim();//Trim函数去除空格
                }
            }
            return "错误";
        }

    }
}

14. 字符串学习1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 字符串学习1
{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            String s = "Hello";
            string s1=s.ToLower();
            Console.WriteLine(s);
            Console.WriteLine(s1);
            s = s.ToLower();//并不是改变了字符串的内容,而是生成一个新的全部变成小写的字符串
            Console.WriteLine(s);
            Console.WriteLine(s.ToUpper());

            string s2="   a  b   ";
            s2 = s2.Trim();//去掉两边的空格
            Console.WriteLine("|{0}|",s2);
            */

            //bool b=("abc"=="ABC");
            bool b = "abc".Equals("ABC",StringComparison.OrdinalIgnoreCase);
            //Ignore:忽略,Case:大小写
            Console.WriteLine(b);

            //字符串比较
            int i = "abc".CompareTo("123");//字符串比较
            Console.WriteLine(i);

            //字符串分隔
            string s1 = "aaa,bbb,ccc,fadsfas.hello|f123,yes";
            string[] strs = s1.Split(',','.','|');//以逗号等多个分隔符分隔字符串
            foreach (string item in strs)
            {
                Console.WriteLine(item);
            }
            Console.WriteLine("------------");
            string s2 = "aaa,bb,cc,12,3";
            string[] strs2 = s2.Split(new char[]{','},StringSplitOptions.RemoveEmptyEntries);
            foreach (string item in strs2)
            {
                Console.WriteLine(item);
            }
            Console.WriteLine("------------");
            string s3 = "我是杰克逊我是麦克杰克逊";
            string[] strs3 = s3.Split(new string[]{"我是"},StringSplitOptions.RemoveEmptyEntries);
            foreach (string item in strs3)
            {
                Console.WriteLine(item);
            }

            //读文件
            Console.WriteLine("------------");
            string[] lines = System.IO.File.ReadAllLines(@"..\..\1.txt",Encoding.Default);
            foreach (string item in lines)
            {
                //Console.WriteLine(item);
                string[] strs4 = item.Split(new string[] { "|" }, StringSplitOptions.RemoveEmptyEntries);
                Console.WriteLine(item+"\t"+strs4[2]);
            }

            Console.ReadKey();
        }
    }
}

15. 字符串学习2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 字符串学习2
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = "李时珍同志是一个好同志，是一个好医生，向李时珍学习";
            s = s.Replace("李时珍","李素丽");//替换字符串
            Console.WriteLine(s);

            string s1 = "http://www.baidu.com";
            string 域名 = s1.Substring(7);//取从第7个字符串开始的字字符串
            Console.WriteLine(域名);

            string s2 = s1.Substring(7,5);//从第7个位置截取5个字符
            Console.WriteLine(s2);

            string s3="我们的社会真和谐！";
            if(s3.Contains("社会")||s3.Contains("和谐"))
            {
                Console.WriteLine("含有敏感词汇，请文明用语！");
            }

            if (s1.StartsWith("http://") || s1.StartsWith("https://"))
            {
                Console.WriteLine("是网址！");
            }
            else
            {
                Console.WriteLine("不是网址！");
            }

            string s4 = "你好，我是王某某";
            int i = s4.IndexOf("我是");
            int i2 = s4.IndexOf("你是");
            Console.WriteLine(i);
            Console.WriteLine(i2);

            Console.ReadKey();
        }
    }
}

程序员的博客

2011年5月30日星期一

C Sharp基础

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