How to display message on toast when raised button is clicked? - flutter

Question

When login button is pressed, I want to show a toast that displays user details in successful or "not found" message otherwise.
new RaisedButton(
onPressed: () {
Future<User> user = _sendToServer();
if (user != null) {
Toast.show("You have logged as ${user.toString()}", context,
duration: Toast.LENGTH_SHORT, gravity: Toast.BOTTOM);
} else {
Toast.show("Not found", context,
duration: Toast.LENGTH_SHORT, gravity: Toast.BOTTOM);
}
},
child: new Text('log in'),
),
I know that I receive the right response but just unable to display it using toast.
Future<User> _sendToServer() async {
DatabaseHelper helper = DatabaseHelper.instance;
if (_key.currentState.validate()) {
// No any error in validation
_key.currentState.save();
User user = await helper.getLogin(email, password);
print("login user ${user.email}");
return user;
} else {
// validation error
setState(() {
_validate = true;
});
return null;
}
}

Answer 1

RaisedButton(
onPressed: () async{ // mark it async
User user = await _sendToServer(); // await to get user
if (user != null) {
Toast.show("You have logged as ${user.toString()}", context,
duration: Toast.LENGTH_SHORT, gravity: Toast.BOTTOM);
} else {
Toast.show("Not found", context,
duration: Toast.LENGTH_SHORT, gravity: Toast.BOTTOM);
}
},
child: new Text('log in'),
)

Answer 2

You should make the onPressed as async and call your function with await or use it like a promise.
For exa -
yourFunctiomWithFuture().then((value) {
// Run code here
}, onError: (error) {
print(error);
});