System.Web.HttpException.WritePageSource C# (CSharp) Method

		static void WritePageSource (StringBuilder builder, HtmlizedException e)
		{
			string s;
			int line = 0;
			int beginerror = e.ErrorLines [0];
			int enderror = e.ErrorLines [1];
			int begin = beginerror - 2;
			int end = enderror + 2;
			if (begin <= 0)
				begin = 1;
			
			TextReader reader = new StringReader (e.FileText);
			while ((s = reader.ReadLine ()) != null) {
				line++;
				if (line < begin)
					continue;

				if (line > end)
					break;

				if (beginerror == line)
					builder.Append ("<span class=\"sourceErrorLine\">");

				builder.AppendFormat ("{0}: {1}\r\n", line, HtmlEncode (s));

				if (enderror <= line) {
					builder.Append ("</span>");
					enderror = end + 1; // one shot
				}
			}
		}