Windows Phone 7 message or gallery events

I am new to Windows phone 7 . I开发者_如何学编程 wanted to ask if there is any way to know or catch the event fired up before opening a Message or Gallery in windows phone 7 so that i can do some password prompt or anything ... I need this feature in developing an application ...Kindly help me out

No, there is not. The OS simply don't allow you to hook into the build-in apps and features.

You can generally not hook into other apps on WP7. The eco-system is simply not designed for it.

You can only do this if messaging and media selectors are invoked from your application, where effectively you are in control of the workflow. Due to the existing security model, however, you cannot interfere with system processes from inside the sandbox.