How to store username after logout and show it in TextInput on next login?
you can use AsyncStorage component of React Native. For more info AsyncStorage
You can set a value of user on logout.
AsyncStorage.setItem('UseName', 'name of user');
On login form get value from AsyncStorage in componentWillMount() method.
AsyncStorage.getItem('UserName')
.then((data) => {
if (data) {
this.setState({UserName:data}) //store data in state
}
}).done();