Class not found in android studio-CodePudding

Hello this is my first post on this site, please be indulgent if I post in a disorganized way So here, I'm supposed to make a mobile application on android studio to scan a qr code, I tried to follow this video https://www.youtube.com/watch?v=RxUyEtXQySA but I'm already blocked in the first steps. especially here https://youtu.be/RxUyEtXQySA?t=58 when I add the code in red, I get two errors

[here's the code] [1]: https://i.stack.imgur.com/247xT.png

[the errors] [2]: https://i.stack.imgur.com/JBLhx.png

what should i do to fix this ?

CodePudding user response：

Try to add current package name with class file 
<com.example.qrcode.CodeScannerView>
// xml code
</com.example.qrcode.CodeScannerView>

CodePudding user response：

can you show me how to add the current package with your class file on this screen ? im sry its my first time on android studio enter image description here