c# - 如何在 FileHelpers 中使用动态 CSV 定界符？

Question

问题:我需要读取 CSV 文件。我使用 FileHelpers 库来实现这一点。

问题是我需要一个动态定界符(用户定义)，这意味着任何东西都可以是定界符(逗号、分号、制表符、换行符，以及其他任何东西)。

问题是，FileHelpers 在属性中定义分隔符，这意味着在编译时。这使得无法动态地执行此操作。

我能做的是声明一个新类，它继承自一个基类，并在这个新类上设置分隔符。

[FileHelpers.DelimitedRecord(",")]
public class CommaCustomer : BaseCustomer
{

}

这样我只需要在基类中为每个新的定界符进行更改。问题是，我不能(也不想)为每个可能的分隔符创建一个子类。

这是我目前的代码:

using System;
using System.Data;
using System.IO;
//using FileHelpers;
//using FileHelpers.RunTime;


namespace Examples
{


    class MainClass
    {


        [STAThread]
        static void Main()
        {
            FileHelpers.FileHelperEngine engine = new FileHelpers.FileHelperEngine(typeof(SemicolonCustomer));

            // To read use:

            string str = @"D:\Username\Desktop\FileHelpers_Examples_CSharp_VbNet\Data\SemicolonCustomers.txt";
            //str = @"D:\Username\Desktop\FileHelpers_Examples_CSharp_VbNet\Data\CustomersDelimited.txt";
            SemicolonCustomer[] custs = (SemicolonCustomer[])engine.ReadFile(str);
            //Customer[] custs = (Customer[]) engine.ReadFile("yourfile.txt");


            foreach (SemicolonCustomer cli in custs)
            {
                Console.WriteLine();
                Console.WriteLine("Customer: " + cli.CustId.ToString() + " - " + cli.Name);
                Console.WriteLine("Added Date: " + cli.AddedDate.ToString("d-M-yyyy"));
                Console.WriteLine("Balance: " + cli.Balance.ToString());
                Console.WriteLine();
                Console.WriteLine("-----------------------------");
            } // Next cli

            Console.ReadKey();
            Console.WriteLine("Writing data to a delimited file...");
            Console.WriteLine();


            // To write use:
            //engine.WriteFile("myyourfile.txt", custs);


            //If you are using .NET 2.0 or greater is 
            //better if you use the Generics version:

            // FileHelperEngine engine = new FileHelperEngine<Customer>();

            // To read use (no casts =)
            // Customer[] custs = engine.ReadFile("yourfile.txt");

            // To write use:
            // engine.WriteFile("yourfile.txt", custs);

        } // End Sub Main


    } // End Class  MainClass


    //------------------------
    //   RECORD CLASS (Example, change at your will)
    //   TIP: Remember to use the wizard to generate this class
    public class BaseCustomer
    {
        public int CustId;

        public string Name;
        public decimal Balance;
        [FileHelpers.FieldConverter(FileHelpers.ConverterKind.Date, "ddMMyyyy")]
        public DateTime AddedDate;
    }


    [FileHelpers.DelimitedRecord(";")]
    public class SemicolonCustomer : BaseCustomer
    {

    }


    [FileHelpers.DelimitedRecord(",")]
    public class CommaCustomer : BaseCustomer
    {

    }


}

是否有可能在运行时编译子类

[FileHelpers.DelimitedRecord(\"" + delimiter + "\")]
public class AnyDelimiterCustomer : BaseCustomer
{           
}

然后在代码中引用这个运行时编译类？

Answer 1

我刚刚意识到有一个 DelimitedFileEngine 可以用另一种方式解决您的问题。

你可以走了

var engine = new DelimitedFileEngine(typeof(BaseCustomer));
engine.Options.Delimiter = ",";

似乎 BaseCustomer 需要用 [DelimitedRecord] 属性修饰，否则会引发异常，但分隔符会被提供给 的内容覆盖engine.Options.Delimiter.

以下示例使用标记为竖线分隔的格式导入逗号分隔的记录。

[DelimitedRecord("|")]
public class Format1
{
    public string Field1;           
    public string Field2;            
    public string Field3;            
    public string Field4;
}

static void Main(string[] args)
{
    var engine = new DelimitedFileEngine(typeof(Format1));
    // change the delimiter
    engine.Options.Delimiter = ","; 

    // import a comma separated record
    object[] importedObjects = engine.ReadString(@"a,b,c,d");

    foreach (object importedObject in importedObjects)
    {
        if (importedObject is Format1)
        {
            Format1 format1 = (Format1)importedObject;
            // process it (for example, check the values)
            Assert.AreEqual("a", format1.Field1);
            Assert.AreEqual("b", format1.Field2);
            Assert.AreEqual("c", format1.Field3);
            Assert.AreEqual("d", format1.Field4);
        }
    }
}