Flutter

问题 So I was trying this code in flutter: void main() => runApp(MyApp()); class MyApp extends StatefulWidget { @override _MyAppState createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { int _i = 1; @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( body: Center( child: MaterialButton( child: Text('You Pressed Me $_i'), onPressed: () { setState(() { _i++; print('inside i = $_i'); }); sleep(Duration(seconds: 10)); _i++; print('outside i = $_i');

问题 So I was trying this code in flutter: void main() => runApp(MyApp()); class MyApp extends StatefulWidget { @override _MyAppState createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { int _i = 1; @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( body: Center( child: MaterialButton( child: Text('You Pressed Me $_i'), onPressed: () { setState(() { _i++; print('inside i = $_i'); }); sleep(Duration(seconds: 10)); _i++; print('outside i = $_i');

问题 I have this code : widget.items.sort((a, b) { await getItemDistance(a, true); await getItemDistance(b, false); return (itemADistance) .compareTo(itemBDistance); }); I am trying to sort widget.items list based on values returned from getItemDistance. However I get an error with a red squiggly line that says : The await expression can only be used in an async function and when I try to add async to the sort method I get another red squiggly line that says : The argument type 'Future Function

问题 Future userPasswordUpdate() async { String passwordU = password.text; String confirmPasswordU = confirmPassword.text; String oldPasswordU = oldPassword.text; var url = 'url'; var response = await http.put(url, headers: { 'Accept': 'application/json' }, body: { "password": passwordU, "confirmPass": confirmPasswordU, "oldpassword": oldPasswordU, } ); I want to post image file to server with this method. But I Don't Know How. Can Anyone Help Me ? 回答1: For the image upload you can also use the

问题 Future userPasswordUpdate() async { String passwordU = password.text; String confirmPasswordU = confirmPassword.text; String oldPasswordU = oldPassword.text; var url = 'url'; var response = await http.put(url, headers: { 'Accept': 'application/json' }, body: { "password": passwordU, "confirmPass": confirmPasswordU, "oldpassword": oldPasswordU, } ); I want to post image file to server with this method. But I Don't Know How. Can Anyone Help Me ? 回答1: For the image upload you can also use the

问题 I just noticed today that whenever I want to query a database I get an error which doesn't really make a sense to me and querying just stop working. It worked just fine few weeks ago. Invalid Query. All where filters with an inequality (lessThan, lessThanOrEqual, greaterThan, or greaterThanOrEqual) must be on the same field. But you have inequality filters on 'value1' and 'value2') Stream<List<MyModel>> myStream( {MyFilter filter, String category}) { return _service.collectionsStream( path:

问题 I just noticed today that whenever I want to query a database I get an error which doesn't really make a sense to me and querying just stop working. It worked just fine few weeks ago. Invalid Query. All where filters with an inequality (lessThan, lessThanOrEqual, greaterThan, or greaterThanOrEqual) must be on the same field. But you have inequality filters on 'value1' and 'value2') Stream<List<MyModel>> myStream( {MyFilter filter, String category}) { return _service.collectionsStream( path:

问题 Flutter hot reloads every time VS Code auto-saves my project before. A few hours ago, I started experiencing this issue where auto-saving doesn't hot-reload my app. Pressing Ctrl+S manually triggers hot reload but auto-saving does not. I've tried re-installing VS Code and Flutter SDK but the problem still exists. My newly installed VS Code only has the following extensions and settings: Dart: v3.19.1 Flutter: v3.19.0 Auto-save is set to afterDelay of 1000ms How do I hot reload when autosaving

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 8 months ago . Improve this question I am building a flutter auction application, I am stuck at the countdown time of an auction product so I use firebase realtime database. I have to make sure all users see the countdown at the same time. Please help me whether it's just a keyword to search

问题 I want to use flutter on my computer, I use Android Studio and Visual Studio Code. when I was running a flutter doctor , a warning like this appeared, [√] Flutter (Channel stable, v1.17.3, on Microsoft Windows [Version 10.0.14393], locale id-ID) [!] Android toolchain - develop for Android devices (Android SDK version 29.0.3) X Android license status unknown. Try re-installing or updating your Android SDK Manager. See https://developer.android.com/studio/#downloads or visit visit https:/