Question

I hope to access visual component (such a button) using tag.
It is easy on android, but I am not sure if it is possible on wp7.

Answer 1

If the controls are in a collection that implements IEnumerable<FrameworkElement> you can use LINQ:

var controlQuery = from ctrl in collection
                   where ctrl.Tag.Equals(thingInTag)
                   select ctrl

If not you would first have to collect all the child controls (it’s WPF but should work in WP7 too)