Question: How to apply headers read from a separate file?

[empz]

I have a CSV file without headers. The headers are located in a separate 1-line CSV file.

These are all dynamic so can't be mapped to a class.

Is there a way to pass CsvReader a list of headers to be used during parsing and construction of the ExpandoObjects?

[AltruCoder]

Not exactly pretty, but something like this might work to combine the streams before reading.

using (var stream = new MemoryStream())
using (var reader = new StreamReader(stream))
using (var writer = new StreamWriter(stream))
using (var csv = new CsvReader(reader))
using (var headerReader = new StreamReader("path\\to\\Header.csv"))
using (var recordReader = new StreamReader("path\\to\\Record.csv"))
{
    headerReader.BaseStream.CopyTo(stream);
    writer.WriteLine();
    writer.Flush();
    recordReader.BaseStream.CopyTo(stream);
    stream.Position = 0;

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

[JoshClose]

Unfortunately that will load the entire file into memory, which could be bad if the file is large.

Another way is to manipulate the context directly.

void Main()
{
	var headerReader = new StringReader("Id,Name\r\n");
	var contentReader = new StringReader("1,one\r\n");
	string[] header;
	using (var csv = new CsvParser(headerReader))
	{
		header = csv.Read();
	}
	
	using (var csv = new CsvReader(contentReader))
	{
		csv.Configuration.HasHeaderRecord = false;
		csv.Context.HeaderRecord = header;
		csv.GetRecords<Foo>().Dump();
	}
}

public class Foo
{
	public int Id { get; set; }
	public string Name { get; set; }
}

[JoshClose]

@AltruCoder You've been answering a lot of questions lately and I want to say thank you. It is tremendously helpful for me.