我有一个简单的控制台应用程序，其中包含 Program.cs 中的 3 个用户的列表。在 Program.cs 中，我想调用
FileOperations.cs首先是我的
Program.csusing System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
class Program
{
static void Main(string[] args)
{
// Create user default instances
User user0 = new User("Beheer", "[email protected]", "123");
User user1 = new User("Inkoop", "[email protected]", "123");
User user2 = new User("Verkoop", "[email protected]", "123");
// List of 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);
// Create login instance
LoginManager loginMgr = new LoginManager();
Start:
// Welcome message
Console.WriteLine("Welcome to GimpiesTerminal! Choose 1 to login or 2 to register:");
// 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)
{
Console.WriteLine("You have successfully logged in !!!");
Console.ReadLine();
successfull = true;
break;
}
}
if (!successfull)
{
Console.WriteLine("Your username or password is incorrect, try again !!!");
}
}
else if (input == "2")
{
// Get user input
Console.WriteLine("Enter your username:");
string username = Console.ReadLine();
Console.WriteLine("Enter your email:");
string email = Console.ReadLine();
Console.WriteLine("Enter your password:");
string password = Console.ReadLine();
// Create fresh instance to save input in memory
User user = new User(username, email, password);
// Adds the user to the excisting list
users.Add(user);
successfull = true;
goto Start;
}
else if (input == "3")
{
// Here I want to call the method from FileOperations.cs to write the List here to a CSV file.
}
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
// }
// }
}
}
}
这是我的
FileOperations.csusing System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using CsvHelper;
namespace GimpiesConsoleOOcsvListUI
{
public class FileOperations
{
// Handles CRUD within CSV files and able to save them
public void SaveToCSV(User user)
{
using (var mem = new MemoryStream())
using (var writer = new StreamWriter(mem))
using (var csvWriter = new CsvWriter(writer))
{
csvWriter.Configuration.Delimiter = ";";
csvWriter.Configuration.HasHeaderRecord = true;
csvWriter.Configuration.AutoMap<User>();
csvWriter.WriteHeader<User>();
csvWriter.WriteRecords(user);
writer.Flush();
var result = Encoding.UTF8.GetString(mem.ToArray());
Console.WriteLine(result);
}
}
}
}
我在
FileOperations.csStreamWriter 作家 参数 1：无法从
System.IO.StreamWriterCsvHelper.ISerializer第 23 行：
用户用户 参数 1：无法从
GimpiesConsoleOOcsvListUI.UserSystem.Collections.IEnumerable我是 C# 新手，所以希望您不要介意这是一个简单的解决问题！ :-)
如果您想序列化单个用户对象并显示其序列化标头和值，可以尝试以下代码：
public void SaveToCSV(List<User> users)
{
var csvConfig = new CsvConfiguration(CultureInfo.CurrentCulture)
{
HasHeaderRecord = true,
Delimiter = ",",
Encoding = Encoding.UTF8
};
using (var mem = new MemoryStream())
using (var writer = new StreamWriter(mem))
using (var csvWriter = new CsvWriter(writer, csvConfig))
{
csvWriter.WriteRecords(users);
writer.Flush();
var result = Encoding.UTF8.GetString(mem.ToArray());
Console.WriteLine(result);
}
}
它使用库的
StringWriterCsvWriterInvariantCultureleaveOpentrueStringWriterusingUserWriteRecordWriteRecords如果您想将其写入实际文件，则必须采取一些不同的做法：
public void SaveToCSV(List<User> users)
{
var csvConfig = new CsvConfiguration(CultureInfo.CurrentCulture)
{
HasHeaderRecord = true,
Delimiter = ",",
Encoding = Encoding.UTF8
};
using (var writer = new StreamWriter(@"path\to\your\file.csv"))
using (var csvWriter = new CsvWriter(writer, csvConfig))
{
csvWriter.WriteRecords(users);
}
}
您不需要在第二个示例中调用
Flushusing您收到错误是因为您在这两种情况下传递了错误的参数类型。
CsvWriterTextWriter解决这个问题的简单方法是添加两个参数：
using (var csvWriter = new CsvWriter(writer, CultureInfo.CurrentCulture, false))
第二个错误是因为
CsvWriter.WriteRecordsIEnumerableList<User>public void SaveToCSV(List<User> users)
{
using (var mem = new MemoryStream())
using (var writer = new StreamWriter(mem))
using (var csvWriter = new CsvWriter(writer, CultureInfo.CurrentCulture, false))
{
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);
}
}
由于 csvhelper 中的
this更改，给定的示例将不起作用。
@Jonathn 的更新代码看起来像 -
public void SaveToCSV(List<User> users)
{
var csvConfig = new CsvConfiguration(CultureInfo.CurrentCulture)
{
HasHeaderRecord = true,
Delimiter = ",",
Encoding = Encoding.UTF8
};
using (var mem = new MemoryStream())
using (var writer = new StreamWriter(mem))
using (var csvWriter = new CsvWriter(writer, csvConfig))
{
csvWriter.WriteHeader<User>();
csvWriter.WriteRecords(users);
writer.Flush();
var result = Encoding.UTF8.GetString(mem.ToArray());
Console.WriteLine(result);
}
}