How to Save Console.WriteLine Output to Text File

Try if this works:

FileStream filestream = new FileStream("out.txt", FileMode.Create);
var streamwriter = new StreamWriter(filestream);
streamwriter.AutoFlush = true;
Console.SetOut(streamwriter);
Console.SetError(streamwriter);

do you want to write code for that or just use command-line feature 'command redirection' as follows:

app.exe >> output.txt

as demonstrated here: http://discomoose.org/2006/05/01/output-redirection-to-a-file-from-the-windows-command-line/ (Archived at archive.org)

EDIT: link dead, here's another example: http://pcsupport.about.com/od/commandlinereference/a/redirect-command-output-to-file.htm

Try this example from this article - Demonstrates redirecting the Console output to a file

using System;
using System.IO;

static public void Main ()
{
    FileStream ostrm;
    StreamWriter writer;
    TextWriter oldOut = Console.Out;
    try
    {
        ostrm = new FileStream ("./Redirect.txt", FileMode.OpenOrCreate, FileAccess.Write);
        writer = new StreamWriter (ostrm);
    }
    catch (Exception e)
    {
        Console.WriteLine ("Cannot open Redirect.txt for writing");
        Console.WriteLine (e.Message);
        return;
    }
    Console.SetOut (writer);
    Console.WriteLine ("This is a line of text");
    Console.WriteLine ("Everything written to Console.Write() or");
    Console.WriteLine ("Console.WriteLine() will be written to a file");
    Console.SetOut (oldOut);
    writer.Close();
    ostrm.Close();
    Console.WriteLine ("Done");
}

For the question:

How to save Console.Writeline Outputs to text file?

I would use Console.SetOut as others have mentioned.

---

However, it looks more like you are keeping track of your program flow. I would consider using Debug or Trace for keeping track of the program state.

It works similar the console except you have more control over your input such as WriteLineIf.

Debug will only operate when in debug mode where as Trace will operate in both debug or release mode.

They both allow for listeners such as output files or the console.

TextWriterTraceListener tr1 = new TextWriterTraceListener(System.Console.Out);
Debug.Listeners.Add(tr1);

TextWriterTraceListener tr2 = new TextWriterTraceListener(System.IO.File.CreateText("Output.txt"));
Debug.Listeners.Add(tr2);

-http://support.microsoft.com/kb/815788