21-12-07-CsvHelper사용법

2021.12.07_CsvHelper사용법

목차

1. CsvHelper설치

2. 기본소스

   • 결과확인하기

3. 다른 자료형 받아오기

   • 기본예제
   • 내 소스에 적용해보기
   • 결과확인

1. CsvHelper설치

• NuGet 패키지 관리 클릭

• CsvHelper 검색 후 설치 진행

2. 기본소스

• Before

  using System;
  
  namespace csvHelperTest
  {
    class Program
    {
        static void Main(string[] args)
        {
            using (var reader = new StreamReader("path\\to\\file.csv"))
            using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
            {
                csv.Context.RegisterClassMap<FooMap>();
                var records = csv.GetRecords<Foo>();
            }
        }
    }
    public class Foo
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
  
    public sealed class FooMap : ClassMap<Foo>
    {
        public FooMap()
        {
            Map(m => m.Id);
            Map(m => m.Name);
        }
    }
  }

• After

  using System;
  
  namespace csvHelperTest
  {
    class Program
    {
     private string _path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "@/csv/file.csv";
        static void Main(string[] args)
        {
            using (var reader = new StreamReader(_path))
            using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
            {
                csv.Context.RegisterClassMap<FooMap>();
                var records = csv.GetRecords<Foo>();
            }
        }
    }
    public class Foo
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
  
    public sealed class FooMap : ClassMap<Foo>
    {
        public FooMap()
        {
            Map(m => m.Id);
            Map(m => m.Name);
        }
    }
  }

• 위와 같이 file.csv파일이 존재해야함

결과 확인하기

• 기본적인 자료형의 경우는 잘 받아옴

3. 다른 자료형 받아오기

• 데이터가 enum 타입인 경우

    public enum ClassInfo
    {
        oneGrade,
        twoGrade,
        threeGrade
    }
    public class Foo
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public ClassInfo Class { get; set; }
    }
    public sealed class FooMap : ClassMap<Foo>
    {
        public FooMap()
        {
            Map(m => m.Id);
            Map(m => m.Name);
            Map(m => m.Class);
        }
    }

기본예제

void Main()
{
    using (var reader = new StreamReader("path\\to\\file.csv"))
    using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
    {
        csv.Context.RegisterClassMap<FooMap>();
        csv.GetRecords<Foo>().ToList().Dump();
    }
}

public class Foo
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Json Json { get; set; }
}

public class Json
{
    public string Foo { get; set; }
}

public class JsonConverter<T> : DefaultTypeConverter
{
    public override object ConvertFromString(string text, IReaderRow row, MemberMapData memberMapData)
    {
        return JsonConvert.DeserializeObject<T>(text);
    }

    public override string ConvertToString(object value, IWriterRow row, MemberMapData memberMapData)
    {
        return JsonConvert.SerializeObject(value);
    }
}

public class FooMap : ClassMap<Foo>
{
    public FooMap()
    {
        Map(m => m.Id);
        Map(m => m.Name);
        Map(m => m.Json).TypeConverter<JsonConverter<Json>>();
    }
}

내 소스에 적용해보기

ClassInfoConverter class

• Before

  public class JsonConverter<T> : DefaultTypeConverter
  {
    public override object ConvertFromString(string text, IReaderRow row, MemberMapData memberMapData)
    {
        return JsonConvert.DeserializeObject<T>(text);
    }
  
    public override string ConvertToString(object value, IWriterRow row, MemberMapData memberMapData)
    {
        return JsonConvert.SerializeObject(value);
    }
  }

• After

    public class ClassInfoConverter<T> : DefaultTypeConverter
    {
        public override object ConvertFromString(string text, IReaderRow row, MemberMapData memberMapData)
        {
           // return ClassInfoConverter.DeserializeObject<T>(text);
           return Enum.Parse<ClassInfo>(text);
        }
  
        public override string ConvertToString(object value, IWriterRow row, MemberMapData memberMapData)
        {
            //return ClassInfoConverter.SerializeObject(value);
            return value.ToString();
        }
    }

FooMap class 변경

• Before

    public sealed class FooMap : ClassMap<Foo>
    {
        public FooMap()
        {
            Map(m => m.Id);
            Map(m => m.Name);
            Map(m => m.Class);
        }
    }

• After

    public sealed class FooMap : ClassMap<Foo>
    {
        public FooMap()
        {
            Map(m => m.Id);
            Map(m => m.Name);
            Map(m => m.Class).TypeConverter<ClassInfoConverter<ClassInfo>>();
        }
    }

  결과 확인하기