How to get raw request body in ASP.NET?

protected void Page_Load(object sender, EventArgs e)
{
    MemoryStream memstream = new MemoryStream();
    Request.InputStream.CopyTo(memstream);
    memstream.Position = ;
    using (StreamReader reader = new StreamReader(memstream))
    {
        string text = reader.ReadToEnd();
    }
}

How to get raw request body in ASP.NET?