C# 使用CsvHelper读取CSV文件
我设法将列表中的内容写入CSV文件。现在，我尝试读取创建的CSV文件，并在控制台应用程序中显示内容。我得到了一个例外，这让我在互联网上找到了一些可能的解决方案。它们都不适用于我的控制台应用程序。我希望你能帮助我 调用FileOperations.cs中的方法的Program.cs中的我的代码：C# 使用CsvHelper读取CSV文件,c#,class,constructor,user-input,csvhelper,C#,Class,Constructor,User Input,Csvhelper,我设法将列表中的内容写入CSV文件。现在，我尝试读取创建的CSV文件，并在控制台应用程序中显示内容。我得到了一个例外，这让我在互联网上找到了一些可能的解决方案。它们都不适用于我的控制台应用程序。我希望你能帮助我 调用FileOperations.cs中的方法的Program.cs中的我的代码： using System; using System.Collections.Generic; using System.IO; using System.Text; using CsvHelper;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
class Program
{
static void Main(string[] args)
{
// First line to skip a row and position all users correctly under the right headers
User user0 = new User("", "", "", "");
// Create user default instances
User user1 = new User("Beheer", "beheer@gimpies.nl", "123", "admin");
User user2 = new User("Inkoop", "inkoop@gimpies.nl", "123", "purchase");
User user3 = new User("Verkoop", "verkoop@gimpies.nl", "123", "sales");
// List of default users (with a list you can add, get and remove items in the list)
List<User> users = new List<User>();
users.Add(user0);
users.Add(user1);
users.Add(user2);
users.Add(user3);
// Create login instance
LoginManager loginMgr = new LoginManager();
// Create stock instance
Stock stock = new Stock();
// Create UserList instance
UserList usrlst = new UserList();
// Call method in UserList.cs
usrlst.Users(users);
Start:
// Welcome message
Console.WriteLine("Welcome to the Gimpies Console Application! Choose 1 to login or 2 to register as guest:");
// Get input from user
string input = Console.ReadLine();
bool successfull = false;
while (!successfull)
{
if(input == "1")
{
Console.WriteLine("Enter your username:");
string username = Console.ReadLine();
Console.WriteLine("Enter your password:");
string password = Console.ReadLine();
foreach (User user in users)
{
if (username == user.UserName && password == user.PassWord && user.UserRole == "admin")
{
// Create Admin instance to be able to call methods in that class
Admin am = new Admin();
// Calling the method in Admin.cs to start Menu logic
am.AdminLoggedIn();
successfull = true;
break;
}
if (username == user.UserName && password == user.PassWord && user.UserRole == "purchase")
{
// Create Purchase instance to be able to call methods in that class
Purchase pc = new Purchase();
// Calling the method in Purchase.cs to start Menu logic
pc.PurchaseLoggedIn();
successfull = true;
break;
}
if (username == user.UserName && password == user.PassWord && user.UserRole == "sales")
{
// Create Sales instance to be able to call methods in that class
Sales sl = new Sales();
// Calling the method in Sales.cs to start Menu logic
sl.SalesLoggedIn();
successfull = true;
break;
}
if (username == user.UserName && password == user.PassWord && user.UserRole == "guest")
{
// Create Guest instance to be able to call methods in that class
Guest gt = new Guest();
// Calling the method in Guest.cs to start Menu logic
gt.GuestLoggedIn();
successfull = true;
break;
}
}
if (!successfull)
{
Console.WriteLine("Your username or password is incorrect, try again !!!");
}
}
else if (input == "2")
{
// Create instance to go to method in class RegisterManager.cs
RegisterManager rm = new RegisterManager();
rm.Register(users);
successfull = true;
goto Start;
}
else if (input == "3")
{
FileOperations fo = new FileOperations();
// Calling the method from FileOperations.cs to write the List here to a CSV file
fo.WriteUsersToCSV(users);
goto Start;
}
else if (input == "4")
{
FileOperations fo = new FileOperations();
// Calling the method from FileOperations.cs to write the List here to a CSV file
fo.ReadUsersFromCSV(users);
goto Start;
}
else
{
Console.WriteLine("Try again !!!");
break;
}
}
// // Loop over stored users within instances inside the list where users are added
// foreach (User user in users)
// {
// if(loginMgr.Login(user))
// {
// // Login successfull
// Console.WriteLine("Login user " + user.UserName);
// }
// else
// {
// // Not successfull
// }
// }
}
}
}
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Globalization;
using System.Linq;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
// Handles CRUD within CSV files and able to save them
public class FileOperations
{
// Writes to CSV file from List
public void WriteUsersToCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var writer = new StreamWriter("users.csv"))
using (var csvWriter = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csvWriter.Configuration.Delimiter = ";";
csvWriter.Configuration.HasHeaderRecord = true;
csvWriter.Configuration.AutoMap<User>();
csvWriter.WriteHeader<User>();
csvWriter.WriteRecords(users);
writer.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
// Console.WriteLine(result);
Console.WriteLine("Data saved to users.csv");
}
}
// Reads from CSV file and displays content from it (Work in progress...)
public void ReadUsersFromCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var reader = new StreamReader("users.csv"))
using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))
{
// csvReader.Configuration.Delimiter = ";";
// csvReader.Configuration.HasHeaderRecord = true;
// csvReader.Configuration.AutoMap<User>();
// csvReader.ReaderHeader<User>();
// var records = csvReader.GetRecords<dynamic>();
// reader.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
csvReader.Read();
csvReader.ReadHeader();
csvReader.Configuration.HeaderValidated = null;
csvReader.Configuration.MissingFieldFound = null;
var records = csvReader.GetRecords<User>();
foreach (var record in records)
{
Console.WriteLine(records);
}
// Console.WriteLine(records);
}
}
// Writes to CSV file from List
public void SaveGimpiesToCSV(List<Gimpies> gimpies)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var writer = new StreamWriter("gimpies.csv"))
using (var csvWriter = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csvWriter.Configuration.Delimiter = ";";
csvWriter.Configuration.HasHeaderRecord = true;
csvWriter.Configuration.AutoMap<Gimpies>();
csvWriter.WriteHeader<Gimpies>();
csvWriter.WriteRecords(gimpies);
writer.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
// Console.WriteLine(result);
}
}
}
}
// Reads from CSV file and displays content from it (Work in progress...)
public void ReadUsersFromCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var reader = new StreamReader("users.csv"))
using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))
{
try
{
csvReader.Configuration.Delimiter = ";";
csvReader.Configuration.IgnoreBlankLines = true;
csvReader.Configuration.HasHeaderRecord = true;
csvReader.Configuration.PrepareHeaderForMatch = (string header, int index) => header.ToLower();
csvReader.Configuration.MissingFieldFound = null;
// csvReader.Configuration.AutoMap<User>();
// csvReader.ReaderHeader<User>();
// var records = csvReader.GetRecords<dynamic>();
// reader.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
csvReader.Read();
csvReader.ReadHeader();
// csvReader.Configuration.HeaderValidated = null;
// Store all content inside a new List as objetcs
var records = csvReader.GetRecords<User>().ToList();
// users.ForEach(Console.WriteLine);
foreach (var record in records)
{
Console.WriteLine(record);
}
}
catch (CsvHelper.HeaderValidationException exception)
{
Console.WriteLine(exception);
}
}
}
namespace GimpiesConsoleOOcsvListUI
{
public class User
{
// Constructor
public User(string username, string email, string password, string userrole)
{
_UserName = username;
_Email = email;
_Password = password;
_UserRole = userrole;
}
private string _UserName;
private string _Email;
private string _Password;
private string _UserRole;
public string UserName
{
get { return _UserName; }
set { _UserName = value; }
}
public string Email
{
get { return _Email; }
set { _Email = value; }
}
public string PassWord
{
get { return _Password; }
set { _Password = value; }
}
public string UserRole
{
get { return _UserRole; }
set { _UserRole = value; }
}
}
}
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
class Program
{
static void Main(string[] args)
{
// First line to skip a row and position all users correctly under the right headers
User user0 = new User("", "", "", "");
// Create user default instances
User user1 = new User("Beheer", "beheer@gimpies.nl", "123", "admin");
User user2 = new User("Inkoop", "inkoop@gimpies.nl", "123", "purchase");
User user3 = new User("Verkoop", "verkoop@gimpies.nl", "123", "sales");
// List of default users (with a list you can add, get and remove items in the list)
List<User> users = new List<User>();
users.Add(user0);
users.Add(user1);
users.Add(user2);
users.Add(user3);
// Create login instance
LoginManager loginMgr = new LoginManager();
// Create stock instance
Stock stock = new Stock();
// Create UserList instance
UserList usrlst = new UserList();
// Call method in UserList.cs
usrlst.Users(users);
Start:
// Welcome message
Console.WriteLine("Welcome to the Gimpies Console Application! Choose 1 to login or 2 to register as guest:");
// Get input from user
string input = Console.ReadLine();
bool successfull = false;
while (!successfull)
{
if(input == "1")
{
Console.WriteLine("Enter your username:");
string username = Console.ReadLine();
Console.WriteLine("Enter your password:");
string password = Console.ReadLine();
foreach (User user in users)
{
if (username == user.UserName && password == user.PassWord && user.UserRole == "admin")
{
// Create Admin instance to be able to call methods in that class
Admin am = new Admin();
// Calling the method in Admin.cs to start Menu logic
am.AdminLoggedIn();
successfull = true;
break;
}
if (username == user.UserName && password == user.PassWord && user.UserRole == "purchase")
{
// Create Purchase instance to be able to call methods in that class
Purchase pc = new Purchase();
// Calling the method in Purchase.cs to start Menu logic
pc.PurchaseLoggedIn();
successfull = true;
break;
}
if (username == user.UserName && password == user.PassWord && user.UserRole == "sales")
{
// Create Sales instance to be able to call methods in that class
Sales sl = new Sales();
// Calling the method in Sales.cs to start Menu logic
sl.SalesLoggedIn();
successfull = true;
break;
}
if (username == user.UserName && password == user.PassWord && user.UserRole == "guest")
{
// Create Guest instance to be able to call methods in that class
Guest gt = new Guest();
// Calling the method in Guest.cs to start Menu logic
gt.GuestLoggedIn();
successfull = true;
break;
}
}
if (!successfull)
{
Console.WriteLine("Your username or password is incorrect, try again !!!");
}
}
else if (input == "2")
{
// Create instance to go to method in class RegisterManager.cs
RegisterManager rm = new RegisterManager();
rm.Register(users);
successfull = true;
goto Start;
}
else if (input == "3")
{
FileOperations fo = new FileOperations();
// Calling the method from FileOperations.cs to write the List here to a CSV file
fo.WriteUsersToCSV(users);
goto Start;
}
else if (input == "4")
{
FileOperations fo = new FileOperations();
// Calling the method from FileOperations.cs to write the List here to a CSV file
fo.ReadUsersFromCSV(users);
goto Start;
}
else
{
Console.WriteLine("Try again !!!");
break;
}
}
// // Loop over stored users within instances inside the list where users are added
// foreach (User user in users)
// {
// if(loginMgr.Login(user))
// {
// // Login successfull
// Console.WriteLine("Login user " + user.UserName);
// }
// else
// {
// // Not successfull
// }
// }
}
}
}
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Globalization;
using System.Linq;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
// Handles CRUD within CSV files and able to save them
public class FileOperations
{
// Writes to CSV file from List
public void WriteUsersToCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var writer = new StreamWriter("users.csv"))
using (var csvWriter = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csvWriter.Configuration.Delimiter = ";";
csvWriter.Configuration.HasHeaderRecord = true;
csvWriter.Configuration.AutoMap<User>();
csvWriter.WriteHeader<User>();
csvWriter.WriteRecords(users);
writer.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
// Console.WriteLine(result);
Console.WriteLine("Data saved to users.csv");
}
}
// Reads from CSV file and displays content from it (Work in progress...)
public void ReadUsersFromCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var reader = new StreamReader("users.csv"))
using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))
{
// csvReader.Configuration.Delimiter = ";";
// csvReader.Configuration.HasHeaderRecord = true;
// csvReader.Configuration.AutoMap<User>();
// csvReader.ReaderHeader<User>();
// var records = csvReader.GetRecords<dynamic>();
// reader.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
csvReader.Read();
csvReader.ReadHeader();
csvReader.Configuration.HeaderValidated = null;
csvReader.Configuration.MissingFieldFound = null;
var records = csvReader.GetRecords<User>();
foreach (var record in records)
{
Console.WriteLine(records);
}
// Console.WriteLine(records);
}
}
// Writes to CSV file from List
public void SaveGimpiesToCSV(List<Gimpies> gimpies)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var writer = new StreamWriter("gimpies.csv"))
using (var csvWriter = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csvWriter.Configuration.Delimiter = ";";
csvWriter.Configuration.HasHeaderRecord = true;
csvWriter.Configuration.AutoMap<Gimpies>();
csvWriter.WriteHeader<Gimpies>();
csvWriter.WriteRecords(gimpies);
writer.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
// Console.WriteLine(result);
}
}
}
}
// Reads from CSV file and displays content from it (Work in progress...)
public void ReadUsersFromCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var reader = new StreamReader("users.csv"))
using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))
{
try
{
csvReader.Configuration.Delimiter = ";";
csvReader.Configuration.IgnoreBlankLines = true;
csvReader.Configuration.HasHeaderRecord = true;
csvReader.Configuration.PrepareHeaderForMatch = (string header, int index) => header.ToLower();
csvReader.Configuration.MissingFieldFound = null;
// csvReader.Configuration.AutoMap<User>();
// csvReader.ReaderHeader<User>();
// var records = csvReader.GetRecords<dynamic>();
// reader.Flush();
// var result = Encoding.UTF8.GetString(mem.ToArray());
csvReader.Read();
csvReader.ReadHeader();
// csvReader.Configuration.HeaderValidated = null;
// Store all content inside a new List as objetcs
var records = csvReader.GetRecords<User>().ToList();
// users.ForEach(Console.WriteLine);
foreach (var record in records)
{
Console.WriteLine(record);
}
}
catch (CsvHelper.HeaderValidationException exception)
{
Console.WriteLine(exception);
}
}
}
我遗漏了什么吗？我设法解决了它。我需要调整foreach循环：
public void ReadUsersFromCSV(List<User> users)
{
// using (var mem = new MemoryStream())
// using (var writer = new StreamWriter(mem))
using (var reader = new StreamReader("users.csv"))
using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))
{
try
{
csvReader.Configuration.Delimiter = ";";
csvReader.Configuration.IgnoreBlankLines = true;
csvReader.Configuration.HasHeaderRecord = true;
csvReader.Configuration.PrepareHeaderForMatch = (string header, int index) => header.ToLower();
csvReader.Configuration.MissingFieldFound = null;
csvReader.Read();
csvReader.ReadHeader();
// Store all content inside a new List as objetcs
var records = csvReader.GetRecords<User>().ToList();
// Loop through the List and show them in Console
foreach (var record in records)
{
Console.WriteLine($"{record.username } {record.email} {record.password} {record.userrole}");
}
}
catch (CsvHelper.HeaderValidationException exception)
{
Console.WriteLine(exception);
}
}
}
public void ReadUsersFromCSV（列出用户）
{
//使用（var mem=new MemoryStream（））
//使用（var编写器=新StreamWriter（mem））
使用（var reader=newstreamreader（“users.csv”））
使用（var csvReader=new csvReader（reader，CultureInfo.InvariantCulture））
{
尝试
{
csvReader.Configuration.Delimiter=“；”；
csvReader.Configuration.IgnoreBlankLines=true；
csvReader.Configuration.HasHeaderRecord=true；
csvReader.Configuration.prepareHeadPerformatch=（字符串头，int索引）=>header.ToLower（）；
csvReader.Configuration.MissingFieldFound=null；
csvReader.Read（）；
csvReader.ReadHeader（）；
//将新列表中的所有内容存储为对象
var records=csvReader.GetRecords（）.ToList（）；
//循环浏览列表并在控制台中显示它们
foreach（记录中的var记录）
{
Console.WriteLine（$“{record.username}{record.email}{record.password}{record.userrole}”）；
}
}
捕获（CsvHelper.HeaderValidationException异常）
{
控制台写入线（例外）；
}
}
}
谢谢，但我从这段视频中学到的最多的是：名字是否可能区分大小写<代码>用户名->
用户名