I have this DataTable:

I'm trying to use the Skender.stocks library

https://daveskender.github.io/Stock.Indicators/guide/

The sample in the page only says:

IEnumerable<Quote> quotes = Mycustomfunction();

How can I use a DataTable in a function or cast to return a IEnumerable<Quote>?

CodePudding user response：

You will need to:

1. Iterate over the DataTable rows
2. Create a new instance of a Quote
3. Input the values from the row into the respective property
4. Add the Quote to a List(Of Quote)

The list would be your IEnumerable from that point.

Here is an example:

Dim quotes As New List(Of Quote)()
For Each row As DataRow In MyDataTable.Rows
    quotes.Add(New Quote() With {
        .Date = Convert.ToDateTime(row.Item("Date")),
        .Open = Convert.ToDecimal(row.Item("Open")),
        .High = Convert.ToDecimal(row.Item("High")),
        .Low = Convert.ToDecimal(row.Item("Low")),
        .Close = Convert.ToDecimal(row.Item("Close")),
        .Volume = Convert.ToDecimal(row.Item("Volume"))
    })
Next

Live Demo: https://dotnetfiddle.net/LgguWG

This is a quick and dirty method if you know that each row will have a value for every column and every column can be converted to its respective data type.

If you wanted to refine it a bit more, you could setup conditional statements attempting to convert the values prior to setting the property of the Quote being added to the collection.

CodePudding user response：

An option is to derive your own Quote class and add a constructor which gets its property values from a DataRow

private class MyQuote : Quote
{
    public MyQuote(DataRow dr)
    {
        this.Date = (DateTime)dr["date"];
        this.Open = (decimal)dr["open"];
        this.High = (decimal)dr["high"];
        this.Low = (decimal)dr["low"];
        this.Close = (decimal)dr["close"];
        this.Volume = (decimal)dr["volume"];
    }
}

or implementing the Interface

private class MyQuote : IQuote
{
    public DateTime Date { get; set; }
    public decimal Open { get; set; }
    public decimal High { get; set; }
    public decimal Low { get; set; }
    public decimal Close { get; set; }
    public decimal Volume { get; set; }
    public MyQuote(DataRow dr)
    {
        this.Date = (DateTime)dr["date"];
        this.Open = (decimal)dr["open"];
        this.High = (decimal)dr["high"];
        this.Low = (decimal)dr["low"];
        this.Close = (decimal)dr["close"];
        this.Volume = (decimal)dr["volume"];
    }
}

Then you can use some LINQ to get it from the DataTable (same for derived class and interface)

var quotes = dt.Select().Select(r => new MyQuote(r));

CodePudding user response：

Many, many thanks to David!!, the complete code in c # for if someone else needs it is like this:

Populate the datatable....

using Skender.Stock.Indicators;




void makedt ()
    {
        dt = new DataTable();
        dt.Clear();
        dt.Columns.Add("Date");
        dt.Columns.Add("Open");
        dt.Columns.Add("High");
        dt.Columns.Add("Low");
        dt.Columns.Add("Close");
        dt.Columns.Add("Volume");

        DataRow _ravi = dt.NewRow();
        _ravi["Date"] = DateTime.Now;
        _ravi["Open"] = "500";
        _ravi["High"] = "500";
        _ravi["Low"] = "500";
        _ravi["Close"] = "500";
        _ravi["Volume"] = "500";
        dt.Rows.Add(_ravi);
        //_ravi.Delete();

        _ravi = dt.NewRow();
        _ravi["Date"] = DateTime.Now;
        _ravi["Open"] = "600";
        _ravi["High"] = "600";
        _ravi["Low"] = "600";
        _ravi["Close"] = "600";
        _ravi["Volume"] = "600";
        dt.Rows.Add(_ravi);
        //_ravi.Delete();

        _ravi = dt.NewRow();
        _ravi["Date"] = DateTime.Now;
        _ravi["Open"] = "700";
        _ravi["High"] = "700";
        _ravi["Low"] = "700";
        _ravi["Close"] = "700";
        _ravi["Volume"] = "700";
        dt.Rows.Add(_ravi);
        //_ravi.Delete();

        _ravi = dt.NewRow();
        _ravi["Date"] = DateTime.Now;
        _ravi["Open"] = "800";
        _ravi["High"] = "800";
        _ravi["Low"] = "800";
        _ravi["Close"] = "800";
        _ravi["Volume"] = "800";
        dt.Rows.Add(_ravi);
        //_ravi.Delete();

        _ravi = dt.NewRow();
        _ravi["Date"] = DateTime.Now;
        _ravi["Open"] = "900";
        _ravi["High"] = "900";
        _ravi["Low"] = "900";
        _ravi["Close"] = "900";
        _ravi["Volume"] = "900";
        dt.Rows.Add(_ravi);
        //_ravi.Delete();
    }

running the procedure......

void method()
    {
        
        List<Quote> _quotes = new List<Quote>();
        foreach (DataRow row in dt.Rows)
            _quotes.Add(new Quote()
            {
                Date = Convert.ToDateTime(row["Date"]),
                Open = Convert.ToDecimal(row["Open"]),
                High = Convert.ToDecimal(row["High"]),
                Low = Convert.ToDecimal(row["Low"]),
                Close = Convert.ToDecimal(row["Close"]),
                Volume = Convert.ToDecimal(row["Volume"])
            });

        string s = "";
        foreach (var quote in _quotes)
        {
            s = s   quote.Date.ToString()   quote.Open.ToString()   quote.High.ToString()   quote.Low.ToString()   quote.Close.ToString();
        } // this for if only for check values

        IEnumerable<Quote> quotes = _quotes;
        IEnumerable<SmaResult> results = quotes.GetSma(2);


    }