C# 通关手册(持续更新……)

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摘要

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String

常用静态方法

string.Compare(string str1,string str2,bool ignoreCase)

按照字典顺序比较字符串  当str1 > str2时，返回1 当str1 = str2时，返回0 当str1 < str2时，返回-1  ignoreCase:true 忽略大小写

string.Concat(string str1,string str2)

　string str=string.Concat("c","#"); //str="c#";

String.Format(string str)

string str=String.Format("今年是{0}年","2022");//str="今年是2022年";

string.IsNullOrEmpty(string str1)

  • 判断字符是否为null或者为空，返回值为bool
string str2=""; bool b2=string.IsNullOrEmpty(str2);//b2=true;  string str3=null; bool b3=string.IsNullOrEmpty(str3);//b3=true;

string.Join(string str,string[] strArr)

  • 将数组strArr中的内容拼接成一个新的字符串，并在对应数组的每两项间添加分隔符str
string strs=string.Join(",",string[]{"w","e","r","t"});//strs="w,e,r,t";

split去重

string update_invoice = FINVO System.CollectionICENUMBER + "," + invoiceNumber; // 追加发票号 string[] oldInvoiceList = update_invoice.Split(new Char[] { ',' }); string update_invoice_str = string.Join(",", oldInvoiceList.Distinct().ToArray());

Contains

  • Contains 判断字符串中是否包含某个字符,返回bool值
string str="我爱编程"; bool b=str.Contains("程");//b=true;

StartsWith/EndsWith

string str="我好喜欢你";  bool b1=str.StartsWith("好");//b1=false;  bool b2-str.EndsWith("你");//b2=true;

Equals

string str1="asd"; string str2="ert";  bool  b = str1.Equals(str2);  //b=false; bool <strName>.Equals(string str, StringComparison.OrdinalIgnoreCase)   //表示不区分大小写

IndexOf/LastIndexOf

  • 判断字符串第一次出现（IndexOf）和最后一次出现（LastIndexOf ）的位置，如果没有出现过则返回值为-1
string str ="今天的雨很大，天很冷";  int i=str.IndexOf("很"); //i=4; int i=str.LastIndexOf("很");//j=8; int m=str.IndexOf("小");//m=-1;

Replace

string str="好困呀"; string s=str.Replace("困","精神");//s="好精神呀";

Insert

  • 在字符串的index位置上插入字符，原来的字符依次后移，变成一个新的字符串
string str="夜深了"; string s=str.Insert(1,"已经");// s="夜已经深了"

Remove

  • 在字符串中移除从startIndex开始，长度为length的字符串，剩下的字符合为一个新的字符串( = .Remove(startIndex,length)?
string str="夜已经深了"; string s=str.Remove(1,2);//s="夜深了";

Split

  • 将字符串以sep数组中的字符分割，分割后得到的内容存到一个数组中（string[] .Split(params char[] sep);）
string str="我，真的、好困；呀"; string[] s=str.Split(new char(){'，','、','；'});//s=string[]{"我","真的","好困","呀"};

Substring

  • 取字符以index开始截取，并截取lenth个字符(string .Substring(index,lenth))
string str="还在下雨"; string s=str.Substring(2,2);//s="下雨";

ToCharArray

  • 将字符串转化为字符数组（.ToCharArray()）
string str="雨已经小了"; char[] s=str.ToCharArray();//s=char[]{'雨',"已","经","小","了"};

Trim

  • 出去两边的空格
string str=" aa "; string s=str.Trim();//s="aa";

ToUpper/ToLower

  • ToUpper（转换为大写）和ToLower（转换为小写）
string s="RaSer"; string s1=s.ToUpper();//s1="RASER"; string s2=s.ToLower();//s2="raser";

API

属性

C# 通关手册(持续更新......)

方法

C# 通关手册(持续更新......)
C# 通关手册(持续更新......)
C# 通关手册(持续更新......)

List

创建List

using System.Collections.Generic; List<string> list = new List<string>(); list.Add("a");

数组去重

using System; using System.Collections.Generic; using System.Linq;  List<string> list1 = new List<string>() {"123","456","789","789" };// ["123","456","789","789"] List<string> newList =  list1.Distinct().ToList(); //["123","456","789"]

数组是否包含

using System; using System.Collections.Generic; using System.Linq;  List<string> list1 = new List<string>() {"123","456","789","789" };// ["123","456","789","789"] if(list1.Contains("123")){ 	 Console.WriteLine(true); }else{ 	 Console.WriteLine(false); }

数组分组

using System; using System.Collections.Generic; using  System.Linq;  List<int>  sqlList = new List<int>(); for(int i=0;i<100;i++){ 	sqlList.Add(i); }  Console.WriteLine(sqlList.ToString()); List<List<int>> sql_batch = sqlList.Select((x, i) => new { Index = i, Value = x }) 			.GroupBy(x => x.Index / 5) //分成5组 			.Select(x => x.Select(v => v.Value).ToList()) 			.ToList(); Console.WriteLine(sql_batch.ToString());

API

属性

C# 通关手册(持续更新......)

方法

C# 通关手册(持续更新......)

HashTable

  • 线程安全，单线程性能不如Dictionary

创建Map

using System;   using System.Collections;  Hashtable table =  new  Hashtable(); //添加的是键值对  table.Add("name",  "zhangsan");  table.Add("age",  10);  table.Add("gender",  "male");

删除指定键的元素

using System; using System.Collections;  Hashtable table =  new  Hashtable(); table.Add("age",  10); //通过Key来删除一个键值对  table.Remove("age");

修改元素

using System; using System.Collections;  Hashtable table =  new  Hashtable(); table.Add("age",  10); //通过Key来修改元素 table["age"]  =  30;

遍历Keys

using System; using System.Collections;  Hashtable table =  new  Hashtable(); //添加的是键值对  table.Add("name",  "zhangsan"); table.Add("age",  10); table.Add("gender",  "male"); ICollection keys = table.Keys; //遍历刚刚获取到的所有的Key foreach (object key in keys) {     //通过Key来获取Value     Console.WriteLine($"{key}={table[key]}"); }

遍历Keys-Values

using System;   using System.Collections;  Hashtable table =  new  Hashtable(); //添加的是键值对  table.Add("name",  "zhangsan");  table.Add("age",  10);   //Hashtable中存储的元素类型是DictionaryEntry foreach (DictionaryEntry entry in table) {    //获取一个键值对中的键    object key = entry.Key;    //获取一个键值对中的值    object value = entry.Value;    Console.WriteLine($"{key}={value}"); }

获取HashTable中的键值对的数目

using System; using System.Collections;  Hashtable table =  new  Hashtable(); int Count = table.Count;

清空集合

using System;   using System.Collections;  Hashtable table =  new  Hashtable(); table.Clear();

判断Hashtable中是否包含了指定的键

using System;   using System.Collections;  Hashtable table =  new  Hashtable(); //添加的是键值对  table.Add("name",  "zhangsan");  table.Add("age",  10);  bool result = table.Contains("age");

Dictionary

创建Map

using System.Collections.Generic;  Dictionary<int,string > dict = new Dictionary<int,string>();  dict.Add(1,"111");  dict.Add(2,"222");

删除指定键的元素

using System.Collections.Generic;  Dictionary< string , int > d = new Dictionary< string , int >(); d.Add( "C#" , 2); d.Add( "VB" , 1); d.Add( "C" , 0); d.Add( "C++" , -1); //删除键为“C”的元素 d.Remove( "C" ); //删除键为“VB”的元素 d.Remove( "VB" );

序列化为JSON对象

using Newtonsoft.Json; using System.Collections.Generic;  Dictionary<string, int> dic = new Dictionary<string, int>() {     {"张三",1},     {"李四",2}, }; string result = JsonConvert.SerializeObject(dic); Console.WriteLine(result); //{"张三":1,"李四":2}

JSON对象反序列化Dictionary

using Newtonsoft.Json; using System.Collections.Generic;  result = "{"张三":1,"李四":2}"; Dictionary<string, int> dic2 = JsonConvert.DeserializeObject<Dictionary<string, int>>(result); foreach (var item in dic2) {     Console.WriteLine($"{item.Key}---->{item.Value}"); }

判断是否存在相应的key并显示

using System.Collections.Generic;  Dictionary<int,string > dict = new Dictionary<int,string>(); if (dict.ContainsKey(<key>))  { 	 Console.WriteLine(dict[<key>]);  }

遍历Keys

using System.Collections.Generic;  Dictionary<int,string > dict = new Dictionary<int,string>(); foreach (var item in dict.Keys) {  Console.WriteLine( "Key:{0}" , item); }

遍历Values

using System.Collections.Generic;  Dictionary<int,string > dict = new Dictionary<int,string>(); foreach (var item in dict.Values) {  Console.WriteLine( "value:{0}" , item); }

遍历整个字典

using System.Collections.Generic;  Dictionary<int,string > dict = new Dictionary<int,string>(); foreach (var item in dict) {  Console.WriteLine( "key:{0} value:{1}" , item.Key, item.Value); }

HashSet

  • 高性能且无序的集合，只能使用foreach来进行迭代，而无法使用for循环。

创建HashSet

using System;  using System.Collections.Generic; HashSet<string> hashSet = new HashSet<string>(); hashSet.Add("A"); hashSet.Add("B"); hashSet.Add("C"); hashSet.Add("D");  // A B C D

判断是否包含

hashSet.Contains("D")

移除某元素

hashSet.Remove(item);

删除所有元素

hashSet.Clear()

判断 HashSet 是否为某一个集合的完全子集

HashSet<string> setA = new HashSet<string>() { "A", "B", "C", "D" }; HashSet<string> setB = new HashSet<string>() { "A", "B", "C", "X" }; HashSet<string> setC = new HashSet<string>() { "A", "B", "C", "D", "E" }; if (setA.IsProperSubsetOf(setC)) //是子集输出1，不是输出0    Console.WriteLine("setC contains all elements of setA."); if (!setA.IsProperSubsetOf(setB))    Console.WriteLine("setB does not contains all elements of setA.");

集合合并

  • 输出setA setB中的所有元素
using System;  using System.Collections.Generic;  HashSet<string> setA = new HashSet<string>() { "A", "B", "C", "D", "E" }; HashSet<string> setB = new HashSet<string>() { "A", "B", "C", "X", "Y" }; setA.UnionWith(setB); foreach(string str in setA) {    Console.WriteLine(str); } //最终setA的输出结果是 A B C D E X Y

交集

  • 输出setA和setB集合中都有的元素
using System;  using System.Collections.Generic;  HashSet<string> setA = new HashSet<string>() { "A", "B", "C", "D", "E" }; HashSet<string> setB = new HashSet<string>() { "A", "B", "C", "X", "Y" }; setA.IntersectWith(setB); // A B C

差集

  • 输出setA集合中有但setB集合中没有的元素
using System; using System.Collections.Generic;  HashSet<string> setA = new HashSet<string>() { "A", "B", "C", "D", "E" }; HashSet<string> setB = new HashSet<string>() { "A", "B", "C", "X", "Y" }; setA.ExceptWith(setB); // D E

两个集合都不全有的元素

HashSet<string> setA = new HashSet<string>() { "A", "B", "C", "D", "E" }; HashSet<string> setB = new HashSet<string>() { "A", "X", "C", "Y" }; setA.SymmetricExceptWith(setB); foreach (string str in setA) {   Console.WriteLine(str); } //对于这个示例，最终输出结果是BDEXY

SortedSet

创建SortedSet

using System; using System.Collections.Generic;  SortedSet<string> set1 = new SortedSet<string>(); set1.Add("CD"); set1.Add("CD"); set1.Add("CD"); set1.Add("CD"); Console.WriteLine("Elements in SortedSet1..."); foreach (string res in set1) { 		Console.WriteLine(res); }

API

C# 通关手册(持续更新......)

Json

创建JSON

金蝶JSON

using Kingdee.BOS.JSON; JSONObject jsonObject = new JSONObject(); jsonObject.Put("userName", dynamicObjectCollection[0]["USERNAME"]); jsonObject.Put("reason", backMsg); jsonObject.Put("bbcOrderNum",billNo);

C# JSON

using Newtonsoft.Json; using Newtonsoft.Json.Linq; JObject jObject = new JObject(); jObject["recMobile"] = Convert.ToString(dynamicObject["FReceiverPhone"]); jObject["recTel"] = Convert.ToString(dynamicObject["FReceiverTel"]);

合并其他对象到属性

JObject obj = new JObject(); obj.Add("name", "张三"); obj.Add("birthday", DateTime.Now);   //合并其他对象到当前对象的属性 obj.Add("content", JToken.FromObject(new {     code = "zhangsan" }));   //返回 { 	"name":"张三", 	"birthday","2022-05-04", 	"content":{ 		"code":"zhangsan" 	} }

合并其他对象的属性，到当前对象

//合并其他 JObject obj = new JObject(); obj.Add("name", "张三"); obj.Add("birthday", DateTime.Now);  JObject obj2 = JObject.FromObject(new {     code = "lisi" }); obj.Merge(obj2);  //返回 { 	"name":"张三", 	"birthday","2022-05-04", 	"code ":"lisi" }

JSON解析

using Newtonsoft.Json; using Newtonsoft.Json.Linq;  string jsonText = @"{  "input": { 	'size': 193156,  	'type': 'image/png' }"; JObject jobject = (JObject)JsonConvert.DeserializeObject(jsonText); decimal input_size = Convert.ToDecimal(jobject["input"]["size"]);//193156, 输入图片大小 string input_type = jobject["input"]["type"].ToString();// "image/png"，输入图片类型

DateTime

字符串转时间

DateTime time= Convert.ToDateTime("2022-04-28 00:00:00"); Console.WriteLine(time);

时间转字符串

DateTime dt_now = DateTime.Now; string time=dt_now.ToString("yyyy-MM-dd hh:mm:ss"); Console.WriteLine(time);

时间字符串格式化 yyyy-MM-dd hh:mm:ss 转 yyMMdd

string time = Convert.ToDateTime("2019-08-28 00:00:00").ToString("yyMMdd"); Console.WriteLine(time);

Thread

创建多线程 无参

//threadMain Console.WriteLine("Main方法开始执行..."); Thread threadA = new Thread(Execute); threadA.Start();  Thread threadB = new Thread(test); threadB.Start(); Console.WriteLine("Main方法执行结束...");  //threadB private void test() {    while (true) {    Console.WriteLine($"test:{DateTime.Now.Ticks}");    } }  //threadA private void Execute() {    Console.WriteLine("开始下载,此协程的Id是:" +            Thread.CurrentThread.ManagedThreadId);   int bill_count = billNoList.Count;   Thread.Sleep(5000 * bill_count);   foreach (string billNo in billNoList)   {     getIvnumber(billNo);   }   Console.WriteLine("下载完成"); }

创建多线程 带参

//定义一个类，用于存放线程需要的数据和线程启动的方法 public class MyThread {   private string data;//线程数据    public MyThread(string data)   {     this.data = data;   }   //线程启动方法   public void ThreadMain()   {     Console.WriteLine("Running in a thread, data: {0}", data);   } } static void Main() {   MyThread obj = new MyThread("info");//创建实例信息   Thread t3 = new Thread(obj.ThreadMain);//启动实例方法   t3.Start(); } 
//定义一个数据类型，传递给线程 public struct Data {   public string Message; } //创建一个方法，将方法给线程的ParameterizedThreadStart委托 static void ThreadMainWithParameters(object obj) {   Data d = (Data)obj;   Console.WriteLine("Running in a thread, received {0}", d.Message); } static void Main() {   Data d = new Data { Message = "Info" };//创建一个数据实例   Thread t2 = new Thread(ThreadMainWithParameters);//创建线程   t2.Start(d);//启动线程，并传递参数 }

线程启动 前台线程/后台线程

//前台线程 //创建线程方法，以在主线程中调用 static void ThreadMain() {   Console.WriteLine("Thread {0} started", Thread.CurrentThread.Name);   Thread.Sleep(3000);   Console.WriteLine("Thread {0} completed", Thread.CurrentThread.Name); } static void Main() {   Thread t1 = new Thread(ThreadMain);  t1.Name = "MyNewThread";   t1.Start();　　 Thread.Sleep(100);   Console.WriteLine("Main thread ending now...");   /*******************输出********************     *          Thread MyNewThread started    *     Main thread ending now...    *     Thread MyNewThread completed    * *****************************************/ } 
//后台线程 static void Main() {   Thread t1 = new Thread(ThreadMain);   t1.Name = "MyNewThread";   t1.IsBackground = true;   t1.Start();   Thread.Sleep(100);   Console.WriteLine("Main thread ending now...");   /*******************输出********************    *     Thread MyNewThread started    *     Main thread ending now...    * *****************************************/ } 
前台线程:主线程默认启动方式为前台线程，主线程结束后，前台线程仍可以活动。 后台线程：如果在线程启动前，将线程的IsBackground属性设置为true，主线程结束时，会终止新线程的执行（不论是否完成任务）。

Ramdom

生成随机数

using System;  Random r = new Random(); Console.WriteLine(r.Next(1,5));

转载请注明来源 https://www.cnblogs.com/brucejiao/p/16188865.html 谢谢！
转载请注明来源 https://www.cnblogs.com/brucejiao/p/16188865.html 谢谢！
转载请注明来源 https://www.cnblogs.com/brucejiao/p/16188865.html 谢谢！

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