You are using constraint layout in which case you'll have to set constraints to the button.
For starters, you can use
start_toStartOf="parent"
top_toTopOf="parent"
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.