将数据从嵌套的 c# 类导出到 csv 文件

Question

我有以下类可以使用，我想将内容导出/展平为 csv 文件。 我尝试使用 SelectMany，但找不到从公司级别 和 SalesArea、Node 和 EthernetArea 的底层级别为我的 csv 文件选择字段的方法。 有人可以解释我需要做什么来完成这个吗？

public class Rootobject
{
    public Company[] Companies { get; set; }
}
public class Company
{
    public string ORG_NAME { get; set; }
    public SalesArea[] Salesareas { get; set; }
    public Node[] Nodes { get; set; }
    public EthernetArea[] Ethernetareas { get; set; }
}
public class SalesArea
{
    public string OBJ_NAME { get; set; }
    public string AREA_CTYPE { get; set; }
}
public class Node
{
    public string OBJ_NAME { get; set; }
    public object BUILDING { get; set; }
}
public class EthernetArea
{
    public string OBJ_NAME { get; set; }
    public string AREA_CTYPE { get; set; }
    public Product[] Products { get; set; }
}
public class Product
{
    public string BANDWIDTH_A { get; set; }
    public string CONNECTION_TYPE { get; set; }
}

Answer 1

我确定应该有另一种方法来做到这一点，但无论如何我就是这样做的......

如果我理解正确，您想对数据进行“非规范化”并将集合导出为 CSV。

我用过很多SelectSelectMany和Join

var root = new Rootobject
    {
        Companies = new Company[] {
            new Company
        {
            ORG_NAME = "Co",
            Salesareas = new SalesArea[]{
            new SalesArea {
                OBJ_NAME = "Sa",
                AREA_CTYPE = "SaAr",
            }
        },
            Nodes = new Node[] {
            new Node {
                OBJ_NAME = "No",
                BUILDING = "NoBu"
            }
        },
            Ethernetareas = new EthernetArea[] {
            new EthernetArea {
                OBJ_NAME = "Et",
                AREA_CTYPE = "EtAr",
                Products = new Product[] {
                    new Product {
                        BANDWIDTH_A = "ProA",
                        CONNECTION_TYPE = "ProCon"
                    }
                }
            }
        }
        },
        new Company
        {
            ORG_NAME = "Co2",
            Salesareas = new SalesArea[]{
            new SalesArea {
                OBJ_NAME = "Sa2",
                AREA_CTYPE = "SaAr2",
            }
        },
            Nodes = new Node[] {
            new Node {
                OBJ_NAME = "No2",
                BUILDING = "NoBu2"
            }
        },
            Ethernetareas = new EthernetArea[] {
            new EthernetArea {
                OBJ_NAME = "Et2",
                AREA_CTYPE = "EtAr2",
                Products = new Product[] {
                    new Product {
                        BANDWIDTH_A = "ProA2",
                        CONNECTION_TYPE = "ProCon2"
                    },
                    new Product {
                        BANDWIDTH_A = "ProA3",
                        CONNECTION_TYPE = "ProCon3"
                    }
                }
            }
        }
        }
    }
    };

    var sas = root.Companies.SelectMany(x => x.Salesareas.Select(y => new { Company = x.ORG_NAME, SalesName = y.OBJ_NAME, SalesAreaType = y.AREA_CTYPE }));
    var nodes = root.Companies.SelectMany(x => x.Nodes.Select(y => new { Company = x.ORG_NAME, NodesName = y.OBJ_NAME, NodeBuilding = y.BUILDING }));
    var ethes = root.Companies.SelectMany(x => x.Ethernetareas.SelectMany(y => y.Products .Select(z => new { Company = x.ORG_NAME, EthernetName = y.OBJ_NAME, EthernetArea = y.AREA_CTYPE, BandwithA = z.BANDWIDTH_A, ConnnectionType = z.CONNECTION_TYPE })));

    sas.Join(nodes, x => x.Company, y => y.Company, (x, y) => new {x.Company, x.SalesName, x.SalesAreaType, y.NodesName, y.NodeBuilding})
        .Join(ethes, x => x.Company, y => y.Company, (x, y) => new {x.Company, x.SalesName, x.SalesAreaType, x.NodesName, x.NodeBuilding, y.EthernetName, y.EthernetArea, y.BandwithA, y.ConnnectionType})
        .Dump();

• Dump() 是 LinqPad 扩展方法

这是结果...

使用集合，您可以按照@Drag And Drop 的建议使用CsvHelper 来生成 CSV 文件.... :)

编辑

我刚刚意识到@Drag And Drop 代码更直接、更简洁、更好...... :)

Answer 2

定义一个类，该类将在 CSV 中表示您想要的内容。由于模型中的多个对象属性具有相同的名称。
在您的评论中，您选择在属性前面加上类名，因此您应该有类似：

public class CompanyCSV
{
    public string Company_ORG_NAME { get; set; }

    public string SalesArea_OBJ_NAME { get; set; }
    public string SalesArea_AREA_CTYPE { get; set; }

    public string Node_OBJ_NAME { get; set; }
    public string Node_BUILDING { get; set; }

    public string EthernetArea_OBJ_NAME { get; set; }
    public string EthernetArea_AREA_CTYPE { get; set; }

    public string Product_BANDWIDTH_A { get; set; }
    public string Product_CONNECTION_TYPE { get; set; }
}

那么简单：

var result = from c in dataInput.Companies
                from s in c.Salesareas
                from n in c.Nodes
                from e in c.Ethernetareas
                from p in e.Products
                select new CompanyCSV
                {
                    Company_ORG_NAME = c.ORG_NAME,

                    SalesArea_OBJ_NAME = s.OBJ_NAME,
                    SalesArea_AREA_CTYPE = s.AREA_CTYPE,

                    Node_OBJ_NAME = n.OBJ_NAME,
                    Node_BUILDING = n.BUILDING.ToString(),

                    EthernetArea_OBJ_NAME = e.OBJ_NAME,
                    EthernetArea_AREA_CTYPE = e.AREA_CTYPE,

                    Product_BANDWIDTH_A = p.BANDWIDTH_A,
                    Product_CONNECTION_TYPE = p.CONNECTION_TYPE
                };


foreach (var line in result)
{ // Don't use this to generate your csv this is simply to show the result
    Console.WriteLine($"{line.c},{line.s},{line.n},{line.e},{line.p}, ..etc ..");
}

要编写 CSV，您可以使用 CsvHelper。 这将帮助您使用逗号或引号处理值。不要手动生成 CSV。

如果您的集合（Node[]、Company[] 等）可以为 null，您应该在 getter 中使用 null-coalescing operator 来保护这种极端情况，例如：

private Node[] nodes;
public Node[] Nodes {
    get { return nodes ?? (nodes = new Node[] { }); }
    set { nodes = value; }
}