使用filehelpers仅读取csv文件的某些列

问题描述 投票：1回答：2

试图只阅读我的csv文件的这些列：Buyer Fullname，Ship to Address1，Ship to Address2，Ship to City，Ship to State，Ship to Zip，Ship to Country，Item Title，Quantity，Sale Price，Shipping and Handling。

这是我的.CSV文件：

Sales Record Number,User Id,Buyer Fullname,Buyer Phone Number,Buyer Email,Buyer Address 1,Buyer Address 2,Buyer City,Buyer State,Buyer Zip,Buyer Country,Item Number,Item Title,Custom Label,Quantity,Sale Price,Shipping and Handling,US Tax,Insurance,Cash on delivery fee,Total Price,Payment Method,Sale Date,Checkout Date,Paid on Date,Shipped on Date,Feedback left,Feedback received,Notes to yourself,PayPal Transaction ID,Shipping Service,Cash on delivery option,Transaction ID,Order ID,Variation Details,Global Shipping Program,Global Shipping Reference ID,Ship To Address 1,Ship To Address 2,Ship To City,Ship To State,Ship To Zip,Ship To Country

"911","trnkaso","TEDDY ROSCO","(815) 814-7454","[email protected]","6300 W Cherry St","","NILES","IL","60454-3406","United States","1115402028","SODIUM HYDROXIDE 50% in a one gallon poly bottle. 4 X 1 GALLON POLY BOTTLES","","2","$25.00","$0.00","$0.00","$0.00","","$100.00","PayPal","Sep-04-15","Sep-04-15","Sep-04-15","","No","","","0FG679030062A","UPS Ground","","1419197650001","","","No","","CHEERY ST","","NILES","IL","60714-3496","United States"
"912","siscokid8","MARK DWAYNE","(408) 943-1485","[email protected]","2050 Dam Ave","","San Jose","CA","95631-2104","United States","111113402518","LACQUER THINNER IN FIVE GALLON METAL PAIL","","1","$50.00","$10.00","$0.00","$0.00","","$153.00","PayPal","Sep-04-15","Sep-04-15","Sep-04-15","","No","","","23432J195640","UPS Ground","","1419241097001","","","No","","205065 Junction Ave","","San DIEGO","CA","95131-2104","United States"
"913","richmeltre","RICHIE FULLBRIGHT","(210) 863-36454","[email protected]","1323 Rosecolored Dr","","York","PA","17655-9185","United States","110829686817","Potassium Permanganate in a five lb container","","1","$35.00","$35.00","$0.00","$0.00","","$70.00","PayPal","Sep-06-15","Sep-06-15","Sep-06-15","","No","","","641682286830F","UPS Ground","","1419745125001","","","No","","ROSE GLASS DR","","York","PA","17244-9175","United States"

3, record(s) downloaded,from ,Sep-04-15,12:34:03, to ,Sep-06-15,04:10:47
Seller ID: [email protected]

不知道如何跳过我不想要的字段，只添加我想要的字段。我想我可以在csv文件中创建虚拟字段，然后在这些项目上执行删除，但是有没有办法从一开始就不包含它们？最后两行也会产生错误我认为，我该如何处理？这里只是我的代码中的一小部分：

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using FileHelpers;

    namespace Ebay
    {
        class Program
        {
            static void Main()
            {
                var engine = new FileHelperEngine<Orders>();
                var records = engine.ReadFile("SalesHistory.csv");
            }  
        }
        [DelimitedRecord(",")]
        [IgnoreEmptyLines]
        class Orders
        {
            public string Name { get; set; }
            public string AddressLine1 { get; set; }
            public string AddressLine2 { get; set; }
            public string City { get; set; }
            public string State { get; set; }
            public string Title { get; set; }
            public string ItemPrice { get; set; }
            public string ShippingPrice { get; set; }
            public string Quantity { get; set; }
            public string PostalCode { get; set; }


        }
    }

这里仍然无法读取文件是我改变代码的方式：

namespace Ebay
{
    class Program
    {
        static void Main()
        {
            var engine = new FileHelperEngine<Orders>();
            var records = engine.ReadFile("SalesHistory.csv");
        }  
    }
    [DelimitedRecord(",")]
    [IgnoreEmptyLines]
    public class Orders
    {
        [FieldOrder(1)]
        private String DummyField1;

        [FieldOrder(2)]
        private String DummyField2;

        [FieldOrder(3)]
        public string Name { get; set; }

        [FieldOrder(4)]
        private String DummyField4;

        [FieldOrder(5)]
        private String DummyField5;

        [FieldOrder(6)]
        private String DummyField6;

        [FieldOrder(7)]
        private String DummyField7;

        [FieldOrder(8)]
        private String DummyField8;

        [FieldOrder(9)]
        private String DummyField9;

        [FieldOrder(10)]
        private String DummyField10;

        [FieldOrder(11)]
        private String DummyField11;

        [FieldOrder(12)]
        private String DummyField12;

        [FieldOrder(13)]
        public string Title { get; set; }

        [FieldOrder(14)]
        private String DummyField14;

        [FieldOrder(15)]
        public string Quantity { get; set; }

        [FieldOrder(16)]
        public string ItemPrice { get; set; }

        [FieldOrder(17)]
        public string ShippingPrice { get; set; }

       [FieldOrder(18)]
        private String DummyField18;

        [FieldOrder(19)]
        private String DummyField19;

        [FieldOrder(20)]
        private String DummyField20;

        [FieldOrder(21)]
        private String DummyField21;

        [FieldOrder(22)]
        private String DummyField22;

        [FieldOrder(23)]
        private String DummyField23;

        [FieldOrder(24)]
        private String DummyField24;

        [FieldOrder(25)]
        private String DummyField25;

        [FieldOrder(26)]
        private String DummyField26;

        [FieldOrder(27)]
        private String DummyField27;

        [FieldOrder(28)]
        private String DummyField28;

        [FieldOrder(29)]
        private String DummyField29;

        [FieldOrder(30)]
        private String DummyField30;

        [FieldOrder(31)]
        private String DummyField31;

        [FieldOrder(32)]
        private String DummyField32;

        [FieldOrder(33)]
        private String DummyField33;

        [FieldOrder(34)]
        private String DummyField34;

        [FieldOrder(35)]
        private String DummyField35;

        [FieldOrder(36)]
        private String DummyField36;

        [FieldOrder(37)]
        private String DummyField37;

        [FieldOrder(38)]
        public string AddressLine1 { get; set; }

        [FieldOrder(39)]
        public string AddressLine2 { get; set; }

        [FieldOrder(40)]
        public string City { get; set; }

        [FieldOrder(41)]
        public string State { get; set; }

        [FieldOrder(42)]
        public string PostalCode { get; set; }

        [FieldOrder(43)]
        public string Country { get; set; }

    }
c# parsing csv filehelpers
2个回答
1
投票

你几乎就在那里，但我还需要添加IgnoreFirst和IgnoreLast属性。否则，最后两行或三行将导致抛出错误，因为它们没有足够的列用于布局。

1
投票

我没有使用过FileHelpers库。永远不需要。这些操作本身并不难。我会做的就像1-2-3一样简单：

  1. 一次读一行;
  2. 拆分线并获得令牌;
  3. 获取必填字段数组中提到的唯一标记。

我们的想法是在Orders类中添加必需的字段，而不是在Main（）中为它编写逻辑。

在代码伪代码组合中，它看起来如下所示：

在Main方法中

public static void Main ()
{
    //Check the file path and other validations etc..

    using (var fileReader = new System.IO.StreamReader(@"C:\your\filepath\here"))
    {
        string line;
        while ((line = fileReader.ReadLine()) != null)
        {
            var tokens = line.Split(',');
            if (tokens.Length != ExpectedLength) continue; //this will filter the non-matching cases, including the last two lines
            myOrders.AddRequiredFields(tokens);
        }
    }
}

在Orders类中

类Orders需要具有的方法只能从每行所有的标记中读取所需的标记。这将会：

//The properties like Name, Title, Quantity are already defined in this class

//Need to define an enum. Good programming practice

enum OrderFieldNumbers
{
    Buyer_Fullname = 0,
    Ship_to_Address1,
    Ship_to_Address2,
    ...,
    Name,
    ...,
    Title,
    ...  //Until all the fields are mentioned
};

public void AddRequiedFields(string[] tokens)
{
    //Simply add the ONLY THOSE FIELDS that you want to read.
    Name = tokens[OrderFieldNumbers.Name];
    Title = tokens[OrderFieldNumbers.Title];
    .
    .
    .
}

每次要阅读特定字段时，请根据需要修改AddRequiredFields。您可能已经枚举了OrderFieldNumbers属性中csv文件的所有字段。因此，您无需记住每个字段的位置。你只需将名称称为OrderFieldNumbers.myNeededColumnNumber就可以了。

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