Call method asynchronously using Delegate

        public delegate string tempDel(string str);

        protected void Page_Load(object sender, EventArgs e)

        {

            tempDel tdel = new tempDel(TestMethod);

            tdel.BeginInvoke("Ajay Patel", callback, tdel);

        }

        private void callback(IAsyncResult ar)

        {

            AsyncResult asynch = (AsyncResult)ar;

            tempDel tdel = asynch.AsyncDelegate as tempDel;

            string str = tdel.EndInvoke(ar); // this will return object,

        // you can then cast it to your return type

       }

        string TestMethod(string str)

        {

            return str;

        }