An C class for reading and writing csv files

This article example for everyone to share a read and write csv file C # class, for your reference, the specific content is as follows

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace CSVDemo
{
 /// <summary>
 /// CSVUtil is a helper class handling csv files.
 /// </summary>
 public class CSVUtil
 {
  private CSVUtil()
  {
  }
  //write a new file, existed file will be overwritten
  public static void WriteCSV(string filePathName,List<String[]>ls)
  {
   WriteCSV(filePathName,false,ls);
  }
  //write a file, existed file will be overwritten if append = false
  public static void WriteCSV(string filePathName,bool append, List<String[]> ls)
  {
   StreamWriter fileWriter=new StreamWriter(filePathName,append,Encoding.Default);
   foreach(String[] strArr in ls)
   {
    fileWriter.WriteLine(String.Join ( " ,",strArr) );
   }
   fileWriter.Flush();
   fileWriter.Close();
   
  }
  public static List<String[]> ReadCSV(string filePathName)
  {
   List<String[]> ls = new List<String[]>();
   StreamReader fileReader=new StreamReader(filePathName); 
   string strLine="";
   while (strLine != null)
   {
    strLine = fileReader.ReadLine();
    if (strLine != null && strLine.Length>0)
    {
     ls.Add(strLine.Split(','));
     //Debug.WriteLine(strLine);
    }
   } 
   fileReader.Close();
   return ls;
  }
  
 }
}