Very clearly , thanks :)
-----邮件原件----- 发件人: [email protected] [mailto:[EMAIL PROTECTED] 代表 Michael Schwarz 发送时间: 2006年6月20日 14:56 收件人: Ajax.NET Professional 主题: [ajaxpro] What is the difference between asynchronous and synchronous calls? Hi, because we have a lot of questions concerning asynchronous and synchronous calls (on client-side JavaScript code) I will list some keywords here: 1) Asynchronous calls: <script type="text/javascript"> function callback(res) { alert(res.value); } function invokeMyMethod() { Namespace.Classname.MyMethod(callback); } </script> a) is the preferred way to call AjaxMethods from the client-side code b) will not freeze web browser application (you are able to click around, move the window, or call another AjaxMethod c) can use client-side timeouts to control what to do if requests needs longer than usual d) a maximum of 2 concurrent requests are possible, and additional requests will be queued and started after one of the 2 concurrent requests is finished 2) Synchronous calls: <scritp type="text/javascript"> function invokeMyMethod() { var res = Namespace.Classname.MyMethod(); alert(res.value); } </script> a) will freeze web browser application (on Internet Explorer the complete content can be invisible because during the request is running the display cannot be updated, you are not able to do other things on the same web page) b) you have to wait until the request is finished, there is no way to abort the request c) only one synchronous request at the same time possible So, please use everytime the asynchronous call because it makes no sense to use the synchronous because of all the disadvantages. -- Best regards | Schöne Grüße Michael Microsoft MVP - Most Valuable Professional Microsoft MCAD - Certified Application Developer http://weblogs.asp.net/mschwarz/ http://www.schwarz-interactive.de/ mailto:[EMAIL PROTECTED] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ajax.NET Professional" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/ajaxpro The latest downloads of Ajax.NET Professional can be found at http://www.ajaxpro.info -~----------~----~----~----~------~----~------~--~---
