how to detect connection in flutter - flutter

Question

so i have this function which detect if there is connection or not . if yes the var activeConnection is true else false . So if the connection is working i'm going to call a method sendEmail() which work with the plugin mailer . My problem is when i activated the WIFI it can send the email then if i turn it off an exception is shown
E/flutter ( 5347): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)]
Unhandled Exception: SocketException: Failed host lookup:
'smtp.gmail.com' (OS Error: No address associated with hostname, errno
= 7)
in this case activeConnection is true but when it try to send the email it can't find the connection . if i turn off the wifi and wait for a moment before i send the email it can detect that there is no wifi so i tried to add a sleep function before it check the connection but i'm facing the same problem .
this is the code :
Future checkUserConnection() async {
try {
//sleep(const Duration(seconds: 10));
final result = await InternetAddress.lookup('google.com');
if (result.isNotEmpty && result[0].rawAddress.isNotEmpty) {
setState(() {
activeConnection = true;
print(activeConnection);
});
}
} on SocketException catch (_) {
setState(() {
activeConnection = false;
print(activeConnection);
});
}
//print(activeConnection);
}
and this is where i call my function
onTap: () {
checkUserConnection();
print(activeConnection);
if (activeConnection) {
sendEmail();
ScaffoldMessenger.of(context).showSnackBar(showSnackBar(
false, "email sended ", Icons.error_outline));
} else {
ScaffoldMessenger.of(context).showSnackBar(showSnackBar(
true,
"check your internet connection !!!",
Icons.error_outline));
}
print("hello");
},

Answer 1

You have to make async function like this:
Future<bool> checkUserConnection() async {
try {
final result = await InternetAddress.lookup('google.com');
if (result.isNotEmpty && result[0].rawAddress.isNotEmpty) {
return true;
}
} on SocketException catch (_) {
return false;
}
}
After that onTap() you have to code like this:
onTap: () {
checkUserConnection().then((activeConnection){
if (activeConnection) {
sendEmail();
ScaffoldMessenger.of(context).showSnackBar(showSnackBar(
false, "email sended ", Icons.error_outline));
} else {
ScaffoldMessenger.of(context).showSnackBar(showSnackBar(
true, "check your internet connection !!!",
Icons.error_outline));
}
});
}