// Example #1: Write an array of strings to a file.

// Create a string array that consists of three lines.
string[] lines = { "First line", "Second line", "Third line" };
// WriteAllLines creates a file, writes a collection of strings to the file,
// and then closes the file.  You do NOT need to call Flush() or Close().
System.IO.File.WriteAllLines(@"C:\Users\Public\DossierTest\WriteLines.txt", lines);

// Example #2: Write one string to a text file.

string text = "A class is the most powerful data type in C#. Like a structure, " + 
              "a class defines the data and behavior of the data type. ";

// WriteAllText creates a file, writes the specified string to the file,
// and then closes the file.    You do NOT need to call Flush() or Close().
System.IO.File.WriteAllText(@"C:\Users\Public\DossierTest\WriteText.txt", text);

// Example #3: Write only some strings in an array to a file.
// The using statement automatically flushes AND CLOSES the stream and calls 
// IDisposable.Dispose on the stream object.
// NOTE: do not use FileStream for text files because it writes bytes, but StreamWriter
// encodes the output as text.

using (System.IO.StreamWriter file = new System.IO.StreamWriter(@"C:\Users\Public\DossierTest\WriteLines2.txt"))
{
     foreach (string line in lines)
     {
        // If the line doesn't contain the word 'Second', write the line to the file.
        if (!line.Contains("Second"))
        {
           file.WriteLine(line);
        }
     }
}

// Example #4: Append new text to an existing file.
// The using statement automatically flushes AND CLOSES the stream and calls 
// IDisposable.Dispose on the stream object.

using (System.IO.StreamWriter file = new System.IO.StreamWriter(@"C:\Users\Public\DossierTest\WriteLines2.txt", true))
{
     file.WriteLine("Fourth line");
}

 //Output (to WriteLines.txt):
 //   First line
 //   Second line
 //   Third line

 //Output (to WriteText.txt):
 //   A class is the most powerful data type in C#. Like a structure, a class defines the data and behavior of the data type.

 //Output to WriteLines2.txt after Example #3:
 //   First line
 //   Third line

 //Output to WriteLines2.txt after Example #4:
 //   First line
 //   Third line
 //   Fourth line