ASP.NET Web服务方法有没有办法使用异步方法？

I have an ASP.NET webservice (.asmx) with a simple method that reads something from the DB with a sync call (ExecuteReader) and returns the result. There is any way to optimize the Thread Pool usage (ie. by calling an async call (BeginExecuteReader)) without changing the method's signature?I have an ASP.NET webservice (.asmx) with a sim