Feature Request - add view load and unload method

[j4587698]

Description

I think view should be away to call load and unload method like page's onappearing and ondisappearing.
It's a very useful method to controlling operations that are required only when the control is displayed.

[AmrAlSayed0]

There is already an issue with the same request #2210 and pull request is in progress #3214

[j4587698]

@AmrAlSayed0 I didn't find this, I'm close this issues, thanks a lot.