AppendText method in C# (Windows Forms)

Question

I am trying to learn C# and ADO.NET using this book: 'Accesing Data with Microsoft .NET Framework 4' by Glenn Johnson. In the third chapter, 'Introducing to LINQ', there is this code snippet:

foreach (var color in results)
{
    txtLog.AppendText(color + Environment.NewLine);
}

Since there are no details of how to create the txtLog file, I tried to do it this way:

StreamWriter txtLog=File.CreateText(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop),"txtLog.txt"));
            foreach (var color in results)
                txtLog=File.AppendText(color + Environment.NewLine);

The problem is Environment.NewLine throws me an error: 'Illegal charactes in path'. After that, I learned that AppendText method takes as argument a path, which pretty much confuses me. How am I supposed to make the code from the book work? The snippet is used multiple times. Thanks.

Answer 1

Well, if you use Windows Forms you can create a new TextBox with the name txtLog. You can see here how to create one.

Then your code will execute just fine without other modifications.

Answer 2

You could use a FileStream to create/append to the file, then a StreamWriter to write to that stream. For example:

    using (FileStream stream = new FileStream("C:\\Path\\FileName.txt", FileMode.Append, FileAccess.Write))
    {
        using (StreamWriter sw = new StreamWriter(stream))
        {
            sw.WriteLine("Your message");
        }
    }

This will create the file if it doesn't exist & append to it if it does exist.