C# 附加到csv文件（csv帮助器）会在csv文件中提供重复条目
使用下面的代码，我尝试将在控制台中输入的用户附加到现有的csv文件中。我正在使用CSV帮助程序，我阅读了文档 首先，我从csv文件加载用户，并使用以下代码将其存储在列表中：C# 附加到csv文件（csv帮助器）会在csv文件中提供重复条目,c#,list,linq,csv,csvhelper,C#,List,Linq,Csv,Csvhelper,使用下面的代码，我尝试将在控制台中输入的用户附加到现有的csv文件中。我正在使用CSV帮助程序，我阅读了文档 首先，我从csv文件加载用户，并使用以下代码将其存储在列表中： using System; using System.Collections.Generic; using System.IO; using System.Text; using System.Globalization; using System.Linq; using CsvHelper; namespace Gimp
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Globalization;
using System.Linq;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
public class UserList
{
public static List<User> LoadUsersFromCSV()
{
// 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.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 users = csvReader.GetRecords<User>().ToList();
return users;
// try
// {
// }
// catch (CsvHelper.HeaderValidationException exception)
// {
// Console.WriteLine(exception);
// }
}
}
}
}
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Globalization;
using System.Linq;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
public class RegisterManager
{
public void Register(List<User> users)
{
// Get user input
Console.WriteLine("Enter username:");
string username = Console.ReadLine();
Console.WriteLine("Enter email:");
string email = Console.ReadLine();
Console.WriteLine("Enter password:");
string password = Console.ReadLine();
Console.WriteLine("Enter userrole (typ admin, purchase or sales):");
string userrole = Console.ReadLine();
// Create fresh instance to save input in memory
User user = new User(username, email, password, userrole);
// Adds the user to the excisting list
users.Add(user);
FileOperations fo = new FileOperations();
// Calling the method from FileOperations.cs to write the List here to a CSV file
fo.WriteUsersToCSV(users);
}
}
}
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Globalization;
using System.Linq;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
class Program
{
static void Main(string[] args)
{
// List of default users
// List<User> users = UserList.DefaultUsers();
// Working on it... Try to read csv file first and try to read list from method in UserList.cs
// UserList ul = new UserList();
List<User> users = UserList.LoadUsersFromCSV();
// List<User> users =
// ul.LoadUsersFromCSV(users);
// Create login instance
LoginManager loginMgr = new LoginManager();
// Create stock instance
Stock stock = new Stock();
Start:
// Welcome message
Console.WriteLine("Welcome to the Gimpies Console Application! Choose 1 to login or 2 to exit this application:");
// Get input from user
string input = Console.ReadLine();
// Set to false to check if login fails or not
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(users);
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(users);
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(users);
successfull = true;
break;
}
}
if (!successfull)
{
Console.WriteLine("Your username or password is incorrect, try again !!!");
}
}
else if (input == "2")
{
Environment.Exit(-1);
}
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();
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
// }
// }
}
}
}
使用系统；
使用System.Collections.Generic；
使用System.IO；
使用系统文本；
利用制度全球化；
使用System.Linq；
使用CsvHelper；
命名空间GimpiesConsolleoCsvListui
{
班级计划
{
静态void Main（字符串[]参数）
{
//默认用户列表
//List users=UserList.DefaultUsers（）；
//正在处理它…首先尝试读取csv文件，然后尝试从UserList.cs中的方法读取列表
//UserList ul=新的UserList（）；
List users=UserList.LoadUsersFromCSV（）；
//列表用户=
//ul.LoadUsersFromCSV（用户）；
//创建登录实例
LoginManager loginMgr=新的LoginManager（）；
//创建股票实例
股票=新股票（）；
开始：
//欢迎辞
WriteLine（“欢迎使用Gimpies控制台应用程序！选择1登录或选择2退出此应用程序：”；
//从用户处获取输入
字符串输入=Console.ReadLine（）；
//设置为false以检查登录是否失败
bool successfull=false；
而（！成功）
{
如果（输入=“1”）
{
Console.WriteLine（“输入您的用户名：”）；
字符串username=Console.ReadLine（）；
Console.WriteLine（“输入密码：”）；
字符串密码=Console.ReadLine（）；
foreach（用户中的用户）
{
if（username==user.username&&password==user.password&&user.userrole==admin）
{
//创建管理实例，以便能够调用该类中的方法
Admin am=新管理员（）；
//调用Admin.cs中的方法以启动菜单逻辑
am.AdminLoggedIn（用户）；
成功=正确；
打破
}
if（username==user.username&&password==user.password&&user.userrole==“购买”）
{
//创建Purchase实例以便能够调用该类中的方法
购买pc=新购买（）；
//调用Purchase.cs中的方法以启动菜单逻辑
pc.PurchaseLoggedIn（用户）；
成功=正确；
打破
}
if（username==user.username&&password==user.password&&user.userrole==sales）
{
//创建销售实例以便能够调用该类中的方法
销售sl=新销售（）；
//调用Sales.cs中的方法以启动菜单逻辑
sl.SalesLoggedIn（用户）；
成功=正确；
打破
}
}
如果（！成功）
{
Console.WriteLine（“您的用户名或密码不正确，请重试！！！”；
}
}
否则如果（输入=“2”）
{
环境。退出（-1）；
}
否则如果（输入=“3”）
{
FileOperations fo=新的FileOperations（）；
//从FileOperations.cs调用该方法以将此处的列表写入CSV文件
fo.WriteUsersToCSV（用户）；
转到开始；
}
否则如果（输入=“4”）
{
FileOperations fo=新的FileOperations（）；
//从FileOperations.cs调用该方法以将此处的列表写入CSV文件
fo.ReadUsersFromCSV（）；
转到开始；
}
其他的
{
Console.WriteLine（“重试！！！”；
打破
}
}
////在添加用户的列表内的实例中循环存储的用户
//foreach（用户中的用户）
// {
//if（loginMgr.Login（用户））
// {
////登录成功
//Console.WriteLine（“登录用户”+user.UserName）；
// }
//否则
// {
////没有成功
// }
// }
}
}
}
还有我的GitLab回购：我为您提供了两种选择。确保您只实现两个选项中的一个 选项#1（代码试图实现的选项），您可以将新记录附加到文件数据。此选项将要求您跟踪文件中已有的内容，以便您可以排除写入文件中已有的记录
username,email,password,userrole,
Inkoop,inkoop@gimpies.nl,123,purchase
Verkoop,verkoop@gimpies.nl,123,sales
Beheer,beheer@gimpies.nl,123,admin
Inkoop,inkoop@gimpies.nl,123,purchase
Verkoop,verkoop@gimpies.nl,123,sales
Beheer,beheer@gimpies.nl,123,admin
Bas,bas@bas.nl,123,admin
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Globalization;
using System.Linq;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
class Program
{
static void Main(string[] args)
{
// List of default users
// List<User> users = UserList.DefaultUsers();
// Working on it... Try to read csv file first and try to read list from method in UserList.cs
// UserList ul = new UserList();
List<User> users = UserList.LoadUsersFromCSV();
// List<User> users =
// ul.LoadUsersFromCSV(users);
// Create login instance
LoginManager loginMgr = new LoginManager();
// Create stock instance
Stock stock = new Stock();
Start:
// Welcome message
Console.WriteLine("Welcome to the Gimpies Console Application! Choose 1 to login or 2 to exit this application:");
// Get input from user
string input = Console.ReadLine();
// Set to false to check if login fails or not
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(users);
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(users);
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(users);
successfull = true;
break;
}
}
if (!successfull)
{
Console.WriteLine("Your username or password is incorrect, try again !!!");
}
}
else if (input == "2")
{
Environment.Exit(-1);
}
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();
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
// }
// }
}
}
}
else if (input == "3")
{
FileOperations fo = new FileOperations();
// get existing users from file
List<User> userInFile = UserList.LoadUsersFromCSV();
// remove existing users from update list to create final list for writing
List<User> finalList = users.Where(u => !userInFile.Any(uf => uf.email.Equals(u.email, StringComparison.InvariantCultureIgnoreCase))).ToList();
fo.WriteUsersToCSV(users);
goto Start;
}
public void WriteUsersToCSV(List<User> users)
{
// overwrite the file each time; indicated by the `false` parameter
using (var writer = new StreamWriter("users.csv", false))
using (var csvWriter = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
// csvWriter.Configuration.HasHeaderRecord = false; // commented out as we write the whole file every time including the header
csvWriter.WriteRecords(users);
Console.WriteLine("New user added to users.csv");
}
}