将字符串csv转换为对象列表

Question

I have the following sting

const string csv = "Foo1,Foo2,Foo3,Foo4,Foo5,Foo6,Ping Pong\n" +
                   "2016-02-29,1437.530029,1445.839966,1433.77002,1436.930054,34016300,1436.930054\n" +
                   "2016-02-25,1431.439941,1431.439941,1421.280029,1426.97998,78076500,1426.97998\n" +
                   "2016-02-24,1430.459961,1432.430054,1417.449951,1419.790039,29049900,1419.790039\n";

How I can convert it to List<Model> where

public class Model
{
    public string Foo1 { get; set; }
    public string Foo2 { get; set; }
    public string Foo3 { get; set; }
    public string Foo4 { get; set; }
    public string Foo5 { get; set; }
    public string Foo6 { get; set; }
    public string Ping_Pong { get; set; }
}

Note of the Ping Pong header in my orig csv

I tried to use CsvHelper but with no success as it is taking a stream rather then string and I failed trying to convert a parse

EDIT It does not matter for me if to use CsvHelper or not, in the end I want to convert the csv to List<Model>

How can I do this?

Answer 1

You can create an StringReader using csv variable:

var textReader = new StringReader(csv);

var csvr = new CsvReader(textReader);
var records = csvr.GetRecords<Model>();

If you want your own parser:

var lines = csv.Split(new char[] {'\n'}, StringSplitOptions.RemoveEmptyEntries).Skip(1);
List<Model> models = new List<Model>();

foreach (var item in lines)
{
    var values = item.Split(',');
    var model = new Model
    {
        Foo1 = values[0],
        Foo2 = values[1],
        Foo3 = values[2],
        Foo4 = values[3],
        Foo5 = values[4],
        Foo6 = values[5],
        Ping_Pong = values[6],
    };

    models.Add(model);
}

EDIT:

To resolve the header problem using CsvHelper you need create a map configuration class specifying the mappings between headers and properties:

public class ModelMap : CsvClassMap<Model>
{
    public ModelMap()
    {
        Map(m => m.Foo1);
        Map(m => m.Foo2);
        Map(m => m.Foo3);
        Map(m => m.Foo4);
        Map(m => m.Foo5);
        Map(m => m.Foo6);
        Map(m => m.Ping_Pong).Name("Ping Pong");
    }
}

Using like this:

var textReader = new StringReader(csv);

var csvr = new CsvReader(textReader);
csvr.Configuration.RegisterClassMap<ModelMap>();

var records = csvr.GetRecords<Model>();

Answer 2

The problem is that your data set (the csv string) is missing a column (you specify 7 columns, but the Ping Pong column is missing from the csv). The default behavior will be to throw, but you can set a config option to ignore missing columns:

Here's working code:

var config = new CsvConfiguration();
// setting this will cause the missing Ping Pong field to be ignored
config.WillThrowOnMissingField = false;

// we wrap your string in a StringReader to make it accessible to CsvReader
var reader = new CsvReader(new StringReader(csv), config);
var records = reader.GetRecords<Model>().ToList();
records.Dump();

Answer 3

To do exactly what you asked you could use this:

var modelStrings = csv.Split('\n').Skip(1);
var models = new List<Model>();
foreach(string s in modelStrings)
{
    var props = s.Split(',');
    models.Add(new Model(props[0],props[1],props[2],props[3],props[4],props[5],props[6]));

}

but a word of warning: this is probably slow, and you might need to add more extensive logic for instantiating new models to account for possible changes in csv format.

Edit:

To clarify what this does, it first splits the csv string by new lines skipping the first one. Then it uses each string in that list and splits them by commas to get a list of values (model properties) to instantiate the Model class with