Sample async example.

SampleAsync.cs

private async Task<string> Execute()
        {
            // Keep watching for out of memory exception when using new string
            string text = "First Line" + Environment.NewLine + "Second" + Environment.NewLine + new string('-', int.MaxValue / 33); 
            text += text;

            StringReader reader = new StringReader(text);

            Console.WriteLine("=Before=");
            string readText = await reader.ReadLineAsync();
            Console.WriteLine("=After=");
            Console.WriteLine(readText);

            return readText;

            /* Result 
             * =Before=
             * =After=
             * First Line
             */
        }

using (var reader = new System.IO.StringReader("My AweSome Test" + new string('-', 200000) + System.Environment.NewLine + "Second Line"))
{
    reader.ReadLineAsync().ContinueWith(t =>
    {
        System.Console.WriteLine(t.Result);
    }); 

    System.Console.WriteLine("-----After-------------");
}