小编die*_*per的帖子

有没有办法更改Flutter项目的包名？

我想在flutter项目中更改包名称和应用程序名称.

当 TextFormField 未激活时，无法更改默认边框颜色。当 TextFormField 未激活时，它会显示 DarkGrey-Border 颜色。那么，如何改变它。

Theme(
              data: new ThemeData(
                primaryColor: Colors.red,
                primaryColorDark: Colors.black,
              ),
              child: TextFormField(
                decoration: new InputDecoration(
                  labelText: "Enter Email",
                  fillColor: Colors.white,
                  border: new OutlineInputBorder(
                    borderRadius: new BorderRadius.circular(25.0),
                    borderSide: new BorderSide(),
                  ),
                  //fillColor: Colors.green
                ),
                validator: (val) {
                  if (val.length == 0) {
                    return "Email cannot be empty";
                  } else {
                    return null;
                  }
                },
                keyboardType: TextInputType.emailAddress,
                style: new TextStyle(
                  fontFamily: "Poppins",
                ),
              ),
            ),

我正在开发一个需要输入价格的应用程序,¥因此没有小数位.如果我们使用,keyboardType: TextInputType.numberWithOptions()我们可以得到一个数字键盘输入.如果我们使用,validator: (input) { }我们可以检查输入是否有效,但我们无法阻止它.

问题是我们可以保存不需要验证的草稿.因此,我们最好只允许数字输入.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Digits Only',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold( …

我正在为我的颤振应用程序尝试 bloc 模式。我想在流值更改时更改文本字段的颜色。

以下是我的区块代码

class Bloc {

  final StreamController<bool> _changeColor = PublishSubject<bool>();

  Function(bool) get changeColour => _changeColor.sink.add;

  Stream<bool> get colour => _changeColor.stream;

  void dispose(){
    _changeColor.close();
  }

}

以下是我继承的小部件

class Provider extends InheritedWidget {

  final bloc = Bloc();
  Provider({Key key,Widget child}): super(key: key,child: child);

  @override
  bool updateShouldNotify(InheritedWidget oldWidget) {
    return true;
  }

  static Bloc of(BuildContext context){
    return (context.inheritFromWidgetOfExactType(Provider) as Provider).bloc;
  }

}

以下是我的主要课程

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {

  @override
  Widget …

我有一个关于如何在Flutter中使用Streams和RxDart调用刷新指示符后重新加载列表的问题.

这是我的,我的模型类:

    class HomeState {

      List<Event> result;
      final bool hasError;
      final bool isLoading;

       HomeState({
        this.result,
        this.hasError = false,
        this.isLoading = false,
      });

      factory HomeState.initial() =>
          new HomeState(result: new List<Event>());
      factory HomeState.loading() => new HomeState(isLoading: true);
      factory HomeState.error() => new HomeState(hasError: true);

    }


    class HomeBloc {

      Stream<HomeState> state;
      final EventRepository repository;

      HomeBloc(this.repository) { 
        state = new Observable.just(new HomeState.initial());
      }

      void loadEvents(){
        state = new Observable.fromFuture(repository.getEventList(1)).map<HomeState>((List<Event> list){
          return new HomeState(
              result: list,
              isLoading: false 
          );    
        }).onErrorReturn(new HomeState.error())
        .startWith(new HomeState.loading());
      }

    }

我的小部件: …

我是 Flutter 开发的新手，我试图显示下拉列表的选定值，但我无法让它工作。

您可以选择一个孩子，它运行良好，但下拉列表并未将其显示为已选择的孩子，就像未选择任何内容一样。

这是我的代码：

import 'package:app2date/repository/repository.dart';
import 'package:app2date/model/FeedSource.dart';
import 'package:app2date/model/FeedCategory.dart';
import 'package:app2date/util/ui.dart';
import 'package:flutter/material.dart';

class ManageFeedSource extends StatefulWidget {
  ManageFeedSource({Key key, this.feedSource}) : super(key: key);

  final FeedSource feedSource;

  @override
  _ManageFeedSource createState() => new _ManageFeedSource();
}

class _ManageFeedSource extends State<ManageFeedSource> {
  final tfNameController = new TextEditingController();
  final tfUrlController = new TextEditingController();
  var editMode = false;
  FeedCategory _feedCategory;

  @override
  Widget build(BuildContext context) {
    FeedSource feedSource = widget.feedSource;
    if (feedSource != null) {
      tfNameController.text = feedSource.name;
      tfUrlController.text = feedSource.url;
      editMode = true; …