如何在 FileHelpers 中使用動態 CSV 分隔符？

Question

問題：我需要讀取一個 CSV 文件。 我使用 FileHelpers 庫來實現這一點。

問題是我需要一個動態定界符（用戶定義），這意味着任何東西都可以是定界符（逗號、分號、制表符、換行符，但也可以是其他任何東西）。

問題是，FileHelpers 在屬性中定義分隔符，這意味着在編譯時。 這使得不可能動態地進行。

我能做的是聲明一個新的 class，它繼承自一個基數 class，並在這個新的 class 上設置分隔符。

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

}

這樣我只需要為每個新的定界符在基礎 class 中進行更改。 問題是，這是我不能（也不想）為每個可能的分隔符創建一個子 class。

這是我到目前為止的代碼：

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
    {

    }


}

是否有可能在運行時編譯子 class

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

然后在代碼中引用這個運行時編譯的 class？

Answer 1

我剛剛意識到有一個DelimitedFileEngine以另一種方式解決了你的問題。

你可以去

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

似乎BaseCustomer需要使用[DelimitedRecord]屬性進行修飾，否則會引發異常，但是提供給engine.Options.Delimiter任何內容都會覆蓋分隔符。

以下示例使用標記為bar分隔的格式導入逗號分隔的記錄。

[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);
        }
    }
}

Answer 2

不，那是不可能的。

但是您可以使用FileHelper DelimitedClassBuilder來構建動態文件解析器，您可以在運行時設置分隔符：

DelimitedClassBuilder dcb = new DelimitedClassBuilder("Name", 
                                 "Here goes your col separator");

// You have to build your field definitions by hand now
dcb.AddField("FieldName", typeof(decimal));
...

// build the engine
DelimitedFileEngine fileEngine = new DelimitedFileEngine(dcb.CreateRecordClass());

// read the file
dynamic[] data = fileEngine.ReadFile(filePath);

Answer 3

您可以使用運行時類 。 你有兩個選擇。 從字符串編譯您的類

例如

// The class definition 
public string mClass =  
@"  
    [DelimitedRecord(""" + delimiter + @""")]
    public class BaseCustomer
    {
        public int CustId;

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

Type t = ClassBuilder.ClassFromString(mClass); 

FileHelperEngine engine = new FileHelperEngine(t); 

DataTable = engine.ReadFileAsDT("test.txt"); 

或者，您可以使用DelimitedClassBuilder類。

DelimitedClassBuilder cb = new DelimitedClassBuilder("BaseCustomer", delimiter);

cb.AddField("CustId", typeof(int));
cb.LastField.TrimMode = TrimMode.Both;
cb.LastField.FieldNullValue = 0;
cb.AddField("Balance", typeof(Decimal));
cb.AddField("AddedDate", typeof(DateTime));

engine = new FileHelperEngine(cb.CreateRecordClass());

DataTable dt = engine.ReadFileAsDT("test.txt");

Answer 4

有可能的。 但只能將序列化類型移動到單獨的程序集中。

像這樣：

using System;
using System.Collections.Generic;
using System.Windows.Forms;


namespace FlaechenupdateScript
{


    static class Program
    {


        // http://www.codeproject.com/KB/cs/runtimecompiling.aspx
        private static System.Reflection.Assembly BuildAssembly(string code)
        {
            Microsoft.CSharp.CSharpCodeProvider provider =
               new Microsoft.CSharp.CSharpCodeProvider();
            System.CodeDom.Compiler.ICodeCompiler compiler = provider.CreateCompiler();
            System.CodeDom.Compiler.CompilerParameters compilerparams = new System.CodeDom.Compiler.CompilerParameters();

            string strLocation = System.Reflection.Assembly.GetExecutingAssembly().Location;
            string strBasePath = System.IO.Path.GetDirectoryName(strLocation);

            string strSerializationTypes = System.IO.Path.Combine(strBasePath, "SerializationTypes.dll");
            string strFileHelpersLocation = System.IO.Path.Combine(strBasePath, "FileHelpers.dll");

            compilerparams.ReferencedAssemblies.Add(strSerializationTypes);
            compilerparams.ReferencedAssemblies.Add(strFileHelpersLocation);

            compilerparams.GenerateExecutable = false;
            compilerparams.GenerateInMemory = true;
            System.CodeDom.Compiler.CompilerResults results =
               compiler.CompileAssemblyFromSource(compilerparams, code);
            if (results.Errors.HasErrors)
            {
                System.Text.StringBuilder errors = new System.Text.StringBuilder("Compiler Errors :\r\n");
                foreach (System.CodeDom.Compiler.CompilerError error in results.Errors)
                {
                    errors.AppendFormat("Line {0},{1}\t: {2}\n",
                           error.Line, error.Column, error.ErrorText);
                }
                throw new Exception(errors.ToString());
            }
            else
            {
                return results.CompiledAssembly;
            }
        } // End Function BuildAssembly


        public static Type GetClassType(Type tt, string strDelimiter)
        {
            string strFullTypeName = tt.FullName;
            string strTypeUniqueName = System.Guid.NewGuid().ToString() + System.Guid.NewGuid().ToString() + System.Guid.NewGuid().ToString() + System.Guid.NewGuid().ToString();
            strTypeUniqueName = "_" + strTypeUniqueName.Replace("-", "_");

            string xx = @"
            namespace CrapLord
            {

                [FileHelpers.IgnoreFirst]
                [FileHelpers.IgnoreEmptyLines]
                [FileHelpers.DelimitedRecord(""" + strDelimiter + @""")]
                public class " + strTypeUniqueName + @" : " + strFullTypeName + @"
                {

                }

            }

            ";

            System.Reflection.Assembly a = BuildAssembly(xx);

            var o = a.CreateInstance("CrapLord." + strTypeUniqueName);
            Type t = o.GetType();

            //System.Reflection.MethodInfo mi = t.GetMethod("EvalCode");
            //var s = mi.Invoke(o, null);

            return t;
        }


        /// <summary>
        /// Der Haupteinstiegspunkt für die Anwendung.
        /// </summary>
        [STAThread]
        static void Main()
        {
            //Application.EnableVisualStyles();
            //Application.SetCompatibleTextRenderingDefault(false);
            //Application.Run(new Form1());

            Type t = GetClassType(typeof(Tools.Serialization.CSV.Customer), ",");

            //FileHelpers.FileHelperEngine engine = new FileHelpers.FileHelperEngine(typeof(SemicolonCustomer));
            FileHelpers.FileHelperEngine engine = new FileHelpers.FileHelperEngine(t);
            string str = "path/to/datafile";
            Tools.Serialization.CSV.Customer[] custs = (Tools.Serialization.CSV.Customer[])engine.ReadFile(str);
            //Customer[] custs = (Customer[]) engine.ReadFile("yourfile.txt");


            foreach (Tools.Serialization.CSV.Customer 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.WriteLine(Environment.NewLine);
            Console.WriteLine(" --- Press any key to continue --- ");
            Console.ReadKey();
        }


    }


}

SerializationTypes程序集：

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


namespace Tools.Serialization.CSV
{

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

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


}

Answer 5

也許你想使用來自Microsoft.VisualBasic.FileIO命名空間的TextFieldParser ：

string[] fields;
string[] delimiter = new string[] { "|" };
using (Microsoft.VisualBasic.FileIO.TextFieldParser parser =
           new Microsoft.VisualBasic.FileIO.TextFieldParser(filename))
{
    parser.Delimiters = delimiter;
    parser.HasFieldsEnclosedInQuotes = false;
    while (!parser.EndOfData)
    {
        fields = parser.ReadFields();

        //Do what you need
    }
}

Answer 6

添加演員表為我解決了問題（FileHelpers V3.5.1）

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