Datasets:
Ekhlass
/
flutter_docs

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
1
372
return null;
}
return 'not a valid email.';
},
onSaved: (val) {
_email = val;
},
decoration: const InputDecoration(
hintText: 'enter your email',
labelText: 'email',
),
),
ElevatedButton(
onPressed: _submit,
child: const Text('Login'),
),
],
),
);
}
<code_end>
the following example shows how form.save() and formKey
(which is a GlobalKey), are used to save the form on submit.
<code_start>
void _submit() {
final form = formKey.currentState;
if (form != null && form.validate()) {
form.save();
showDialog(
context: context,
builder: (context) {
return AlertDialog(
title: const Text('Alert'),
content: Text('Email: $_email, password: $_password'));
},
);
}
}
<code_end>
<topic_end>
<topic_start>
platform-specific code
when building a cross-platform app, you want to re-use as much code as
possible across platforms. however, scenarios might arise where it
makes sense for the code to be different depending on the OS.
this requires a separate implementation by declaring a specific platform.
in react native, the following implementation would be used:
in flutter, use the following implementation:
<code_start>
final platform = theme.of(context).platform;
if (platform == TargetPlatform.iOS) {
return 'ios';
}
if (platform == TargetPlatform.android) {
return 'android';
}
if (platform == TargetPlatform.fuchsia) {
return 'fuchsia';
}
return 'not recognized ';
<code_end>
<topic_end>
<topic_start>
debugging
<topic_end>
<topic_start>
what tools can i use to debug my app in flutter?
use the DevTools suite for debugging flutter or dart apps.
DevTools includes support for profiling, examining the heap,
inspecting the widget tree, logging diagnostics, debugging,
observing executed lines of code, debugging memory leaks and memory
fragmentation. for more information, see the
DevTools documentation.
if you’re using an IDE,
you can debug your application using the IDE’s debugger.
<topic_end>
<topic_start>
how do i perform a hot reload?
flutter’s stateful hot reload feature helps you quickly and easily experiment,
build UIs, add features, and fix bugs. instead of recompiling your app
every time you make a change, you can hot reload your app instantly.
the app is updated to reflect your change,
and the current state of the app is preserved.
in react native,
the shortcut is ⌘r for the iOS simulator and tapping r twice on
android emulators.
in flutter, if you are using IntelliJ IDE or android studio,
you can select save all (⌘s/ctrl-s), or you can click the
hot reload button on the toolbar. if you
are running the app at the command line using flutter run,
type r in the terminal window.
you can also perform a full restart by typing r in the
terminal window.
<topic_end>
<topic_start>
how do i access the in-app developer menu?
in react native, the developer menu can be accessed by shaking your device: ⌘d
for the iOS simulator or ⌘m for android emulator.
in flutter, if you are using an IDE, you can use the IDE tools. if you start
your application using flutter run you can also access the menu by typing h