为什么IsCallback在Master页面中不起作用？

Question

I am using a Master page and I have to perform a function on initial load. I'm using Ajax and devExpress controls so I have to check !IsPostback and !IsCallback. When I try to use IsCallback the intelisense doesn't work and if I write it anyway I get an error message "The name IsCallback doesn't exist in the current context". However with Page.IsCallback intelisense works and no error message is given.

Is there an explenation for this? Is there a problem with checking callbacks in master pages?

Answer 1

Actual explanation is simple enough: MasterPage class itself defines only IsPostback , and does not define IsCallback . Page class on the other hand has both these properties. That is why intellisense gave you nothing in for sole IsCallback .

I believe the reason behind this is that master pages are not designed to differentiate between types of requests - this job is left for pages. In any way callback is just a special type of postback. In other words IsCallback is true only when IsPostback is true, so IsPostback should suffice for your need.