解释下这段代码 越详细越好

Question

namespace AJAXBaseHome
{
    public partial class AutoComplete : System.Web.UI.Page
    {
        private static string conString = WebConfigurationManager.ConnectionStrings["SqlConnectionString"].ConnectionString;        protected void Page_Load(object sender, EventArgs e)
        {
            string input = GetInput();
            Response.Write(GetCompanyName(input));
          
        }        //获取输入的字符串
        private string GetInput()
        {
            Stream s = Request.InputStream;
            int count = 0;
            byte[] buffer = new byte[1024];
            StringBuilder builder = new StringBuilder();
            while ((count = s.Read(buffer, 0, 1024)) > 0)
            {
                builder.Append(Encoding.UTF8.GetString(buffer, 0, count));
            }            return builder.ToString();
        }        private string GetCompanyName(string input)
        {
            using (SqlConnection con = new SqlConnection(conString))
            {
                SqlCommand command = new SqlCommand("select top 10 * from UserInfo where NickName like @Name", con);//("select * from suppliers where CompanyName like @Name", con);
                command.Parameters.Add(new SqlParameter("@name", input + "%"));
                SqlDataAdapter adapter = new SqlDataAdapter(command);
                DataSet ds = new DataSet();
                adapter.Fill(ds);
                return ds.GetXml();
            }
        }
    }
}