You didn't get an answer because you didn't ask a question.
All you did was post irrelevant code, and shout at us: "I NEED TO CREATE A SEARCH BAR IN MY UWP APP"
Shouting is rude: that's probably why you were downvoted.
Not showing any effort? That's not going to get you responses.
If you want answers, you have to ask questions, and they have to make sense.
Remember, we have no idea what you are trying to do, or where you are starting from. We don't even have any idea where you are stuck, or what help you might need unless you specifically tell us.
So start here: Asking questions is a skill
] and think about what you need to know, and what you need to tell us in order to get help when you ask next time.