C# 通關手冊(持續更新……)

2022 年 5 月 21 日
筆記
c#

轉載請註明來源 //www.cnblogs.com/brucejiao/p/16188865.html 謝謝！
轉載請註明來源 //www.cnblogs.com/brucejiao/p/16188865.html 謝謝！
轉載請註明來源 //www.cnblogs.com/brucejiao/p/16188865.html 謝謝！

String

常用靜態方法

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

按照字典順序比較字符串

當str1 > str2時，返回1
當str1 = str2時，返回0
當str1 < str2時，返回-1

ignoreCase:true 忽略大小寫

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)

判斷字符是否為null或者為空，返回值為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)

將數組strArr中的內容拼接成一個新的字符串，並在對應數組的每兩項間添加分隔符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; // 追加發票號
string[] oldInvoiceList = update_invoice.Split(new Char[] { ',' });
string update_invoice_str = string.Join(",", oldInvoiceList.Distinct().ToArray());

Contains

Contains 判斷字符串中是否包含某個字符,返回bool值

string str="我愛編程";
bool b=str.Contains("程");//b=true;

StartsWith/EndsWith

string str="我好喜歡你";

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)   //表示不區分大小寫

IndexOf/LastIndexOf

判斷字符串第一次出現（IndexOf）和最後一次出現（LastIndexOf ）的位置，如果沒有出現過則返回值為-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="好睏呀";
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，原來的字符依次後移，變成一個新的字符串

string str="夜深了";
string s=str.Insert(1,"已經");// s="夜已經深了"

Remove

在字符串中移除從startIndex開始，長度為length的字符串，剩下的字符合為一個新的字符串( = .Remove(startIndex,length)😉

string str="夜已經深了";
string s=str.Remove(1,2);//s="夜深了";

Split

將字符串以sep數組中的字符分割，分割後得到的內容存到一個數組中（string[] .Split(params char[] sep);）

string str="我，真的、好睏；呀";
string[] s=str.Split(new char(){'，','、','；'});//s=string[]{"我","真的","好睏","呀"};

Substring

取字符以index開始截取，並截取lenth個字符(string .Substring(index,lenth))

string str="還在下雨";
string s=str.Substring(2,2);//s="下雨";

ToCharArray

將字符串轉化為字符數組（.ToCharArray()）

string str="雨已經小了";
char[] s=str.ToCharArray();//s=char[]{'雨',"已","經","小","了"};

Trim

出去兩邊的空格

string str=" aa ";
string s=str.Trim();//s="aa";

ToUpper/ToLower

ToUpper（轉換為大寫）和ToLower（轉換為小寫）

string s="RaSer";
string s1=s.ToUpper();//s1="RASER";
string s2=s.ToLower();//s2="raser";

API

屬性

方法

List

創建List

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

數組去重

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"]

數組是否包含

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);
}

數組分組

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組
			.Select(x => x.Select(v => v.Value).ToList())
			.ToList();
Console.WriteLine(sql_batch.ToString());

API

屬性

方法

HashTable

線程安全，單線程性能不如Dictionary

創建Map

using System;  
using System.Collections;

Hashtable table =  new  Hashtable();
//添加的是鍵值對 
table.Add("name",  "zhangsan"); 
table.Add("age",  10); 
table.Add("gender",  "male");

刪除指定鍵的元素

using System;
using System.Collections;

Hashtable table =  new  Hashtable();
table.Add("age",  10);
//通過Key來刪除一個鍵值對 
table.Remove("age");

修改元素

using System;
using System.Collections;

Hashtable table =  new  Hashtable();
table.Add("age",  10);
//通過Key來修改元素
table["age"]  =  30;

遍歷Keys

using System;
using System.Collections;

Hashtable table =  new  Hashtable();
//添加的是鍵值對 
table.Add("name",  "zhangsan");
table.Add("age",  10);
table.Add("gender",  "male");
ICollection keys = table.Keys;
//遍歷剛剛獲取到的所有的Key
foreach (object key in keys)
{
    //通過Key來獲取Value
    Console.WriteLine($"{key}={table[key]}");
}

遍歷Keys-Values

using System;  
using System.Collections;

Hashtable table =  new  Hashtable();
//添加的是鍵值對 
table.Add("name",  "zhangsan"); 
table.Add("age",  10); 

//Hashtable中存儲的元素類型是DictionaryEntry
foreach (DictionaryEntry entry in table)
{
   //獲取一個鍵值對中的鍵
   object key = entry.Key;
   //獲取一個鍵值對中的值
   object value = entry.Value;
   Console.WriteLine($"{key}={value}");
}

獲取HashTable中的鍵值對的數目

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();

判斷Hashtable中是否包含了指定的鍵

using System;  
using System.Collections;

Hashtable table =  new  Hashtable();
//添加的是鍵值對 
table.Add("name",  "zhangsan"); 
table.Add("age",  10); 
bool result = table.Contains("age");

Dictionary

創建Map

using System.Collections.Generic;

Dictionary<int,string > dict = new Dictionary<int,string>();

dict.Add(1,"111");

dict.Add(2,"222");

刪除指定鍵的元素

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);
//刪除鍵為「C」的元素
d.Remove( "C" );
//刪除鍵為「VB」的元素
d.Remove( "VB" );

序列化為JSON對象

using Newtonsoft.Json;
using System.Collections.Generic;

Dictionary<string, int> dic = new Dictionary<string, int>() {
    {"張三",1},
    {"李四",2},
};
string result = JsonConvert.SerializeObject(dic);
Console.WriteLine(result); //{"張三":1,"李四":2}

JSON對象反序列化Dictionary

using Newtonsoft.Json;
using System.Collections.Generic;

result = "{\"張三\":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}");
}

判斷是否存在相應的key並顯示

using System.Collections.Generic;

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

遍歷Keys

using System.Collections.Generic;

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

遍歷Values

using System.Collections.Generic;

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

遍歷整個字典

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

高性能且無序的集合，只能使用foreach來進行迭代，而無法使用for循環。

創建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

判斷是否包含

hashSet.Contains("D")

移除某元素

hashSet.Remove(item);

刪除所有元素

hashSet.Clear()

判斷 HashSet 是否為某一個集合的完全子集

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)) //是子集輸出1，不是輸出0
   Console.WriteLine("setC contains all elements of setA.");
if (!setA.IsProperSubsetOf(setB))
   Console.WriteLine("setB does not contains all elements of setA.");

集合合併

輸出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);
}
//最終setA的輸出結果是 A B C D E X Y

交集

輸出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

輸出setA集合中有但setB集合中沒有的元素

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

兩個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);
}
//對於這個示例，最終輸出結果是BDEXY

SortedSet

創建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

Json

創建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"]);

合併其他對象到屬性

JObject obj = new JObject();
obj.Add("name", "張三");
obj.Add("birthday", DateTime.Now);
 
//合併其他對象到當前對象的屬性
obj.Add("content", JToken.FromObject(new
{
    code = "zhangsan"
}));


//返回
{
	"name":"張三",
	"birthday","2022-05-04",
	"content":{
		"code":"zhangsan"
	}
}

合併其他對象的屬性，到當前對象

//合併其他
JObject obj = new JObject();
obj.Add("name", "張三");
obj.Add("birthday", DateTime.Now);

JObject obj2 = JObject.FromObject(new
{
    code = "lisi"
});
obj.Merge(obj2);

//返回
{
	"name":"張三",
	"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, 輸入圖片大小
string input_type = jobject["input"]["type"].ToString();// "image/png"，輸入圖片類型

DateTime

字符串轉時間

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

時間轉字符串

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

時間字符串格式化 yyyy-MM-dd hh:mm:ss 轉 yyMMdd

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

Thread

創建多線程無參

//threadMain
Console.WriteLine("Main方法開始執行...");
Thread threadA = new Thread(Execute);
threadA.Start();

Thread threadB = new Thread(test);
threadB.Start();
Console.WriteLine("Main方法執行結束...");

//threadB
private void test() {
   while (true) {
   Console.WriteLine($"test:{DateTime.Now.Ticks}");
   }
}

//threadA
private void Execute() {
   Console.WriteLine("開始下載,此協程的Id是:" +            Thread.CurrentThread.ManagedThreadId);
  int bill_count = billNoList.Count;
  Thread.Sleep(5000 * bill_count);
  foreach (string billNo in billNoList)
  {
    getIvnumber(billNo);
  }
  Console.WriteLine("下載完成");
}

創建多線程帶參

//定義一個類，用於存放線程需要的數據和線程啟動的方法
public class MyThread
{
  private string data;//線程數據

  public MyThread(string data)
  {
    this.data = data;
  }
  //線程啟動方法
  public void ThreadMain()
  {
    Console.WriteLine("Running in a thread, data: {0}", data);
  }
}
static void Main()
{
  MyThread obj = new MyThread("info");//創建實例信息
  Thread t3 = new Thread(obj.ThreadMain);//啟動實例方法
  t3.Start();
}

//定義一個數據類型，傳遞給線程
public struct Data
{
  public string Message;
}
//創建一個方法，將方法給線程的ParameterizedThreadStart委託
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" };//創建一個數據實例
  Thread t2 = new Thread(ThreadMainWithParameters);//創建線程
  t2.Start(d);//啟動線程，並傳遞參數
}

線程啟動前台線程/後台線程

//前台線程
//創建線程方法，以在主線程中調用
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...");
  /*******************輸出********************     *          Thread MyNewThread started
   *     Main thread ending now...
   *     Thread MyNewThread completed
   * *****************************************/
}

//後台線程
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...");
  /*******************輸出********************
   *     Thread MyNewThread started
   *     Main thread ending now...
   * *****************************************/
}

前台線程:主線程默認啟動方式為前台線程，主線程結束後，前台線程仍可以活動。
後台線程：如果在線程啟動前，將線程的IsBackground屬性設置為true，主線程結束時，會終止新線程的執行（不論是否完成任務）。

Ramdom

生成隨機數

using System;

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

Tags: c#

C# 通關手冊(持續更新……)

String

常用靜態方法

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

string.Concat(string str1,string str2)

String.Format(string str)

string.IsNullOrEmpty(string str1)

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

split去重

Contains

StartsWith/EndsWith

Equals

IndexOf/LastIndexOf

Replace

Insert

Remove

Split

Substring

ToCharArray

Trim

ToUpper/ToLower

API

屬性

方法

List

創建List

數組去重

數組是否包含

數組分組

API

屬性

方法

HashTable

創建Map

刪除指定鍵的元素

修改元素

遍歷Keys

遍歷Keys-Values

獲取HashTable中的鍵值對的數目

清空集合

判斷Hashtable中是否包含了指定的鍵

Dictionary

創建Map

刪除指定鍵的元素

序列化為JSON對象

JSON對象反序列化Dictionary

判斷是否存在相應的key並顯示

遍歷Keys

遍歷Values

遍歷整個字典

HashSet

創建HashSet

判斷是否包含

移除某元素

刪除所有元素

判斷 HashSet 是否為某一個集合的完全子集

集合合併

交集

差集

兩個集合都不全有的元素

SortedSet

創建SortedSet

API

Json

創建JSON

金蝶JSON

C# JSON

合併其他對象到屬性

合併其他對象的屬性，到當前對象

JSON解析

DateTime

字符串轉時間

時間轉字符串

時間字符串格式化 yyyy-MM-dd hh:mm:ss 轉 yyMMdd

Thread

創建多線程 無參

創建多線程 帶參

線程啟動 前台線程/後台線程

Ramdom

生成隨機數

創建多線程無參

創建多線程帶參

線程啟動前台線程/後台線程

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