Converting HTML entities to Unicode Characters in C#

Question

I found similar questions and answers for Python and Javascript, but not for C# or any other WinRT compatible language.

The reason I think I need it, is because I\'

Answer 1

This worked for me, replaces both common and unicode entities.

private static readonly Regex HtmlEntityRegex = new Regex("&(#)?([a-zA-Z0-9]*);");

public static string HtmlDecode(this string html)
{
    if (html.IsNullOrEmpty()) return html;
    return HtmlEntityRegex.Replace(html, x => x.Groups[1].Value == "#"
        ? ((char)int.Parse(x.Groups[2].Value)).ToString()
        : HttpUtility.HtmlDecode(x.Groups[0].Value));
}

[Test]
[TestCase(null, null)]
[TestCase("", "")]
[TestCase("'fark'", "'fark'")]
[TestCase(""fark"", "\"fark\"")]
public void should_remove_html_entities(string html, string expected)
{
    html.HtmlDecode().ShouldEqual(expected);
}