FileInfo - AppendAllLines

A FileInfo extension method that opens a text file, appends all lines, and then closes the file.

Try it

public static string FileName = "test.txt";

public static void Main()
{
	SaveFile();
	
	string [] lines = {"	<h2>This is <i>italic</i> heading</h2>", 
					   "</body>", 
					   "</html>"};
	
	// C# Extension Method: FileInfo - AppendAllLines
	FileName.ToFileInfo().AppendAllLines(lines);
	
	// C# Extension Method: FileInfo - ReadAllLines
	var allLines = FileName.ToFileInfo().ReadAllLines();
	
	foreach(string line in allLines)
	{
		Console.WriteLine(line);
	}
}

private static void SaveFile()
{
	var html =
    @"<!DOCTYPE html>
<html>
<body>
<h1>This is <b>bold</b> heading</h1>
<p>This is <u>underlined</u> paragraph</p>
";
	
	html.SaveAs(FileName);
}

View Source 
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

public static partial class Extensions
{
    /// <summary>
    ///     A FileInfo extension method that appends all lines.
    /// </summary>
    /// <param name="this">The @this to act on.</param>
    /// <param name="contents">The contents.</param>
    public static void AppendAllLines(this FileInfo @this, IEnumerable<String> contents)
    {
        File.AppendAllLines(@this.FullName, contents);
    }

    /// <summary>
    ///     A FileInfo extension method that appends all lines.
    /// </summary>
    /// <param name="this">The @this to act on.</param>
    /// <param name="contents">The contents.</param>
    /// <param name="encoding">The encoding.</param>
    public static void AppendAllLines(this FileInfo @this, IEnumerable<String> contents, Encoding encoding)
    {
        File.AppendAllLines(@this.FullName, contents, encoding);
    }
}