c#入门常用代码实例.docx

c#入门常用代码实例1.namespace ConsoleApplication1class Programstatic void Main(string args)Console.WriteLine("Hello");string s = Console.ReadLine;/string v= "/"ab/""Console.WriteLine(s);int i1 = 12, i2 = 13;Console.WriteLine("i1+i2="+(i1+i2);Console.WriteLine("0+1=2",i1,i2,i1+i2);Console.ReadKey;2.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication2class Programstatic void Main(string args)Console.Write("Input:");string s1 = Console.ReadLine;int i = Convert.ToInt32(s1);Console.Write("0",i); Console.ReadKey;3.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication4class Programstatic void Main(string args)int i=2;bool b=(i=1);Console.WriteLine("0", i = 1);Console.WriteLine("0", b);Console.ReadKey;4.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication6class Programstatic void Main(string args)/*string s = "I'm kungge."s = s.Replace("kungge","wankun");/替代某个窜Console.WriteLine(s);*/ /*string s = ""string Website = s.Substring(7);Console.WriteLine(Website);string s1 = s.Substring(7,7);Console.WriteLine(s1);*/*string s = "TMD I'll be strong!"if (s.Contains("TMD") | s.Contains("strong")Console.WriteLine("The words are not good!please use them well!");*/* string s = ""if (s.StartsWith("http:/") | s.StartsWith("https:/")Console.WriteLine("It's a website!");/s.EndWith;*/string s = "I'm good enough!"int i = s.IndexOf("good");/字符串中的第几个位置int k = s.IndexOf("well");Console.WriteLine(i);Console.WriteLine(k);Console.ReadKey;5.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication7class Programstatic void Main(string args)/*string s=Console.ReadLine;string words = s.Split(' ');for (int i = words.Length - 1; i &gt= 0; i-)Console.Write( wordsi);*/*Console.WriteLine("Input:");string emil = Console.ReadLine;int a=emil.IndexOf('');string uname = emil.Substring(0,a);string website = emil.Substring(a+1);Console.WriteLine(uname);Console.WriteLine(website);*/*string lines = System.IO.File.ReadAllLines("d:test.txt",Encoding.Default);/注意这种用法foreach (string line in lines)string strs = line.Split(new char' ',StringSplitOptions.RemoveEmptyEntries);/注意这种用法string title=strs0;string author=strs1;title = title.Substring(0,Math.Min(17,title.Length);title = title + "."Console.WriteLine("0|1",title,author);*/string value = G("d:w.ini","姓名");Console.WriteLine(value);Console.ReadKey;static string G(string filename, string itemname)/？注意这个用法string lines = System.IO.File.ReadAllLines(filename, Encoding.Default);foreach (string line in lines)string strs = line.Split('=');string name =strs0;string value =strs1;if (name.Trim = itemname)return value.Trim;return "wrong"6.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication8class Programstatic void Main(string args)/*int age = 21;/A(ref age);A(out age);Console.Write(age);*/int i;string str=Console.ReadLine; if(int.TryParse(str,out i)Console.WriteLine("Successfull 0",i);elseConsole.WriteLine("Wrong");Console.ReadKey;/*static void A(ref int age)/！注意ref和out的区别age+;*/*static void A(out int age)age = 30;age+;*/7.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace 常量和静态成员class Programpublic const double pi = 3.1415926;/常量static void Main(string args)Person.Totalcount = 20;/Person.Age = 20;/错误,非静态的字段、方法或属性“常量和静态成员.Person.Age”要求对象引用Doit;Console.WriteLine(Person.Totalcount);Dog d = new Dog;d.Jiao;Person.People;Person p = new Person;p.Age = 19;p.Hello;/ ConsoleHelper h=nwe ConsoleHelper;/静态类不能被实例化，其一般用来实现数据库ConsoleHelper.ReadInt;Console.ReadKey;public static void DoitConsole.WriteLine("sdfsd");Console.WriteLine(Person.Totalcount);public class Personpublic static int Totalcount;public int Age;public static void PeopleConsole.WriteLine("The people:0",Person .Totalcount);/Console.WriteLine("The people:0 Age: 1", Totalcount,Age);/在static成员中不能调用非static成员public void HelloConsole.WriteLine("People:0 Age:1",Totalcount ,Age);/在非static成员中可以调用static成员public class Dogpublic void JiaoConsole.WriteLine("Wangw:0", Person.Totalcount);static class ConsoleHelper/这是一个静态类public static int ReadIntstring str = Console.ReadLine;return Convert.ToInt32(str);8.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)Console.WriteLine("input two nums:");string str1 = Console.ReadLine;string str2 = Console.ReadLine;while (str1 != "admin")Console.WriteLine("用户名不存在，请重新输入:");str1 = Console.ReadLine;str2 = Console.ReadLine;while (str2 != "888888")Console.WriteLine("密码错误，请重新输入:");str2 = Console.ReadLine;if (str1 = "admin" && str2 = "888888")Console.WriteLine("欢迎!");Console.ReadKey;9.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)int max = 0;while (true)Console.WriteLine("请输入一个数，结束时输入end:");string str = Console.ReadLine;if (str = "end")Console.WriteLine("最大数：0", max);return;int i = Convert.ToInt32(str);if (i &gt max)max = i;Console.ReadKey;10.continue的用法using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)int i=1;int sum = 0;while (i &lt= 100)if (i % 7 = 0)i+;continue;sum = sum + i;i+; Console.WriteLine(sum);Console.ReadKey;11.枚举的用法：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5enum Gender=male,female,unknown;class Programstatic void Main(string args)Gender g1=Gender .female;Gender g2=Gender.male ;Gender g3=Gender .unknown ;Console.ReadKey;12.数组：namespace ConsoleApplication5class Programstatic void Main(string args)/*string strs=new string5;strs0 = "one"strs1="two"*/string strs = "one","two","three" ;string s = ""for (int i = 0; i &lt strs.Length - 1; i+)s = s+strsi+ "|"s=s+strsstrs.Length -1;Console.WriteLine(s);Console.ReadKey;13.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)int t = 1,2,3,4 ;string strs = new stringt.Length;for (int i = 0; i &lt t.Length; i+)strsi = Convert.ToString(ti);for (int i = 0; i &lt t.Length; i+)Console.WriteLine(strsi);Console.ReadKey; 14.foreach 循环的用法：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)string strs = "one","two","three" ;foreach (string str in strs)Console.WriteLine("0",str);Console.ReadKey; 15.函数案例1：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)string strs = "one","two","three" ;Console.WriteLine(S(strs,"|");Console.ReadKey; static string S(string strs,string sep)string s=""for(int i=0;i&ltstrs.Length -1;i+)s = s + strsi + sep;if (strs.Length &gt 0)s = s + strsstrs.Length - 1;return s;16.函数的可变参数：关键字paramsusing System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)V("one","two","three","four");Vt("Kungge", "ping", "swimming", "programming");Console.ReadKey; /static void V(string strs)/不加关键字params就会出错static void V(params string strs)foreach (string str in strs)Console.WriteLine(str);return;static void Vt(string name, params string strs)foreach (string str in strs)Console.WriteLine("My name is 0,My hobby:1", name, str);return;17.函数重载：相同的函数名必须保证参数不同18.字符串处理：string s="Hello"s.Length;s2;重要特性：不可变性(指的是内存中的字符串不可变) 只能通过索引来读取指定的位置的char，不能对指定的位置的char进行修改如果对char进行修改就需要创建一个新的字符串，用s.ToCharArray方法得到字符串的char数组.using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)string s = "hello"char chars = s.ToCharArray;chars0 = 'H'string s2 = new string(chars);Console.WriteLine(s);Console.WriteLine(s2);Console.ReadKey; 19.string常用函数：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication5class Programstatic void Main(string args)string s = "Hello" string s2 = s.ToLower;/转化为小写/string s2 = s.ToUpper;string s3 = " hello "string s4 = s3.Trim;/trim去掉两边的空格Console.WriteLine(s3);Console.WriteLine(s4);Console.WriteLine(s);Console.WriteLine(s2);bool b = ("abc"="ABC");bool b2 = "abc".Equals("ABC",StringComparison.OrdinalIgnoreCase);int i = "abc".CompareTo("ABC");Console.WriteLine(i);Console.WriteLine(b2);string s5 = "aa,bb,cc"string strs = s5.Split(',');/这里面也可以定义多个分隔符foreach (string str in strs)Console.WriteLine(str);string s6 = "aa,bb,cc,dd,ee"string strs2 = s6.Split(new char',',StringSplitOptions .RemoveEmptyEntries);/将字符串按照指定的char分隔符分割成字符串数组/opinion取RemoveEmptyEntries是移除结果中的空白字符串foreach (string str in strs2)Console.WriteLine(str);string s7 = "我爱祖国我爱人民我爱和平"string strs3 = s7.Split(new string "我爱" , StringSplitOptions.RemoveEmptyEntries);/将字符串按照指定的string分隔符分割成字符串数组foreach (string str in strs3)Console.WriteLine(str);Console.ReadKey; 20.练习一：namespace ConsoleApplication5class Programstatic void Main(string args)string lines = System.IO.File.ReadAllLines("e:test.txt", Encoding.Default);foreach (string str in lines)Console.WriteLine(str);Console.ReadKey; 21.接19：其它的什么IndexOf等上面有实例代码，这里不做介绍了22.练习二：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace _11class Programstatic void Main(string args)string lines = System.IO.File.ReadAllLines("E:test2.txt", Encoding.Default);foreach (string line in lines)/string str = line.Split(' ');string str = line.Split(new char' ',StringSplitOptions.RemoveEmptyEntries);string title = str0;string writer=str1;title = title.Substring(0,Math .Min(17,title.Length );if (title.Length &gt 17)/ 为什么这个无法实现title = title + "."Console.WriteLine("Title:0 Writer;1",title,writer );Console.ReadKey;23.练习三：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace _12class Programstatic void Main(string args)string value= G("e:test3.ini","Cname");Console.WriteLine(value);Console.ReadKey;static string G(string filename, string itemname)string lines = System.IO.File.ReadAllLines(filename, Encoding.Default);foreach (string line in lines)/string str = line.Split(new char '=' , StringSplitOptions.RemoveEmptyEntries);/这个可以用一下string str = line.Split('=');string name = str0;string value = str1;if (name.Trim = itemname)return value.Trim ;/return value;return "Wrong"24.练习四：简易聊天版机器人using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace _13class Programstatic void Main(string args)int full=3;Console.WriteLine("你好，我是机器人");while(true)string str=Console.ReadLine ;if (str.Contains("你") && (str.Contains("名字")|str .Contains ("姓名")Console.WriteLine("我是K1，请多多指教");else if(str.Contains ("你")&&str.Contains ("女朋友")Console .WriteLine ("我还没有了，要不你给我介绍一个");else if(str.Contains ("今天")&&str.Contains ("天气")Console .WriteLine ("天气很好");else if (str.Contains("你") && str.Contains("吃饭")Console.WriteLine("我已经吃过了");else if (str.Contains("再见") | str.Contains("拜")|str.Contains ("8")Console.WriteLine("拜，下次聊");return;elseConsole.WriteLine("听不懂");full-;if(full&lt0)Console.WriteLine ("我饿了，给我点东西吃！");Console.WriteLine("请输入数字给我喂食");int i=Convert .ToInt32 (Console.ReadLine );if(i&gt5&&i&lt10)full=full+i;Console.WriteLine ("好饱啊");else if (i &lt 0)Console.WriteLine("小子，你玩我的吧");return;elsefull = full + i;Console.WriteLine("可以了");Console.ReadKey;25.ref和out参数：using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace _11class Programstatic void Main(string args)int i = 20;Increase(ref i);Inc(out i);Console.WriteLine(i);int b;string str = Console.ReadLine;Console.WriteLine(int.TryParse (str,out b);/注意这个用法Console.ReadKey;static void Increase(ref int a)a+;Console.WriteLine(a);static void Inc(out int b)b = 30;b+;Console.WriteLine(b);/注：这是在.Net传智播客视频教学中学C#基础时做的课堂笔记整理 今发布于此只为方便大家学习 仅供参考 由于本人也是初学者 如有错误请见谅 请自行更正！