CSVHelper：一行，多个类映射

问题描述

我有一行是多个类的组合。此后，这些类表示嵌套的聚合对象。 例如：

（标题）product_name，product_sku，product_description，promotion_date，promotion_price

（数据）xxx，1234，“优质产品”，12/4 / 202、3.41美元

我想读取Product对象中的前3个cols，然后将其另两个读取到Promotion对象中。 我可以用两张地图吗？我可以在classMap中的两个类之间创建视图吗？

解决方法

您可以使用多张地图

public class Program
{
    static void Main(string[] args)
    {
        using (var stream = new MemoryStream())
        using (var writer = new StreamWriter(stream))
        using (var reader = new StreamReader(stream))
        using (var csv = new CsvReader(reader,CultureInfo.InvariantCulture))
        {
            writer.WriteLine("product_name,product_sku,product_description,promotion_date,promotion_price");
            writer.WriteLine("xxx,1234,great product,12/4/202,$3.41");
            writer.Flush();
            stream.Position = 0;

            csv.Configuration.RegisterClassMap<TransactionMap>();

            var records = csv.GetRecords<Transaction>().ToList();
        }
    }
}

public class TransactionMap : ClassMap<Transaction>
{
    public TransactionMap()
    {
        References<ProductMap>(m => m.Product);
        References<PromotionMap>(m => m.Promotion);
    }
}

public class ProductMap : ClassMap<Product>
{
    public ProductMap()
    {
        Map(m => m.Name).Name("product_name");
        Map(m => m.Sku).Name("product_sku");
        Map(m => m.Description).Name("product_description");
    }
}

public class PromotionMap : ClassMap<Promotion>
{
    public PromotionMap()
    {
        Map(m => m.Date).Name("promotion_date");
        Map(m => m.Price).Name("promotion_price");
    }
}

public class Transaction
{
    public Product Product { get; set; }
    public Promotion Promotion { get; set; }
}

public class Product
{
    public string Name { get; set; }
    public string Sku { get; set; }
    public string Description { get; set; }
}

public class Promotion
{
    public DateTime Date { get; set; }
    public string Price { get; set; }
}

或一张地图

public class Program
{
    static void Main(string[] args)
    {
        using (var stream = new MemoryStream())
        using (var writer = new StreamWriter(stream))
        using (var reader = new StreamReader(stream))
        using (var csv = new CsvReader(reader,$3.41");
            writer.Flush();
            stream.Position = 0;

            csv.Configuration.RegisterClassMap<TransactionMap>();

            var records = csv.GetRecords<Transaction>().ToList();
        }
    }
}

public class TransactionMap : ClassMap<Transaction>
{
    public TransactionMap()
    {
        Map(m => m.Product.Name).Name("product_name");
        Map(m => m.Product.Sku).Name("product_sku");
        Map(m => m.Product.Description).Name("product_description");
        Map(m => m.Promotion.Date).Name("promotion_date");
        Map(m => m.Promotion.Price).Name("promotion_price");
    }
}

public class Transaction
{
    public Product Product { get; set; }
    public Promotion Promotion { get; set; }
}

public class Product
{
    public string Name { get; set; }
    public string Sku { get; set; }
    public string Description { get; set; }
}

public class Promotion
{
    public DateTime Date { get; set; }
    public string Price { get; set; }
}