Please help me to find problem!

[maplebaby]

I run your code, it's right.
but I do as your way, the log is right, navigator isn't hidden.

I commit code
https://github.com/maplebaby/React-native-demo/blob/master/page/Tran.js
https://github.com/maplebaby/React-native-demo/blob/master/page/TranList.js